Financial Calculators — Free &amp; Transparent

50/30/20 Budget Calculator

Build a 50/30/20 budget from your income and see exactly where every dollar should go

Savings Rate Calculator

Calculate your savings rate and see how it affects your path to financial independence. FI number, years to FI, projected retirement balance, and a sensitivity table across 5–70% savings rates.

Formula

FI number = annual_expenses × 25 (4% rule)

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Debt Payoff Calculator

Compare debt snowball vs avalanche — find your fastest path to debt freedom

Formula

Payoff = -n × ln(1 - i×P/M) / ln(1+i)

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Retirement Savings Calculator

Find out if you're on track to retire comfortably. See your projected balance, inflation-adjusted income, and exactly how much more to save each month to close any gap.

Formula

FV = PMT × [(1+r)ⁿ - 1] / r

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Net Worth Calculator

What are you actually worth? Enter assets and liabilities (including business equity and business loans) — get net worth, liquid net worth, debt-to-asset ratio, wealth rating, next milestone, and a 10-year trajectory.

Formula

net worth = total assets − total liabilities

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Financial Snapshot

Four calculators chained into one: net income after SE tax → full tax picture → monthly cash flow → retirement projection. Generates a shareable snapshot of your entire financial picture.

Formula

Income → Tax → Cash Flow → FV = PV(1+r)ⁿ + PMT[(1+r)ⁿ−1]/r

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Retirement Readiness Score

Are you actually on track to retire? Get a 0–100 readiness score based on projected balance, 4% rule income, Social Security, and your monthly expense target. Includes employer match modeling and Fidelity age benchmarks.

Formula

FV = PV×(1+r)ⁿ + PMT×((1+r)ⁿ−1)/r → income = FV×4%÷12

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Roth vs Traditional IRA

Compare Roth and Traditional IRA after-tax outcomes side by side. Enter your current and expected retirement tax brackets to see which account wins, the break-even retirement rate, and whether a Roth conversion makes sense for your situation.

Formula

Roth net = contribution × (1+r)^n, Trad net = FV × (1−tax_rate)

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401(k) Contribution Optimizer

Find the optimal 401(k) contribution to maximize your employer match, minimize taxes, and hit your retirement goal. Shows the real cost of under-contributing — before and after employer match.

Formula

FV = PMT × ((1+r)ⁿ − 1) ÷ r

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Car Loan Calculator

Calculate your monthly payment, total interest, and true cost of any auto loan. See a full amortization schedule and compare the impact of different down payments.

Formula

PMT = P × r ÷ (1 − (1+r)^−n)

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Personal Loan Calculator

Calculate monthly payments, total interest, and true cost for any personal loan. Compare how term length and rate affect your bottom line — with the full amortization schedule.

Formula

PMT = P × r ÷ (1 − (1+r)^−n)

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Loan Comparison Calculator

Compare up to 3 loan offers side by side — monthly payment, total interest, and true cost.

Debt-to-Income Ratio Calculator

DTI is the primary number lenders use to approve mortgages. Contractors get flagged because lenders use 2-year net income, not gross revenue. See your front-end and back-end DTI, loan qualification status, and exactly how much debt to pay off or income to add to qualify.

Formula

DTI = total_monthly_debt ÷ gross_income × 100

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Effective Tax Rate Calculator

Your marginal bracket isn't what you actually pay. See your combined effective rate across federal, SE/FICA, and state — for W-2 or 1099 income. Bracket breakdown, take-home pay, and income scenario table.

Formula

effective_rate = total_tax ÷ gross_income

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Social Security Estimator

Estimate your Social Security benefit at different claiming ages — 62, 67, or 70.

Federal Income Tax Estimator

Estimate your 2024 federal income tax, effective rate, and refund or amount owed. Includes bracket breakdown, itemized deductions, and withholding analysis.

Payoff vs Invest

Should you pay off your mortgage early or invest the extra? Punch in your numbers, see both paths side by side, get a plain-English recommendation.

Stock Profit/Loss Calculator

Calculate your stock trade profit or loss including taxes and fees

Portfolio Rebalancer

Find out exactly how much to buy or sell to rebalance your investment portfolio

Wheel Strategy Scanner

Systematic options income engine. Sell cash-secured puts, collect premium, sell covered calls. Connected to Alpaca paper trading.

Options Profit Calculator

Calculate profit, loss, and breakeven for call and put options strategies.

Currency Converter

Convert between currencies with live-ish rates and historical context

Politician Trade Signals

Live feed of politician stock trades scraped from Capitol Trades. Searchable, filterable, with alerts when your watchlist gets hit.

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Compound Interest Calculator

See how your money grows with compound interest and regular contributions. Watch year-by-year growth, apply the Rule of 72, and see the real power of compounding.

Formula

A = P(1 + r/n)^(nt)

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Emergency Fund Calculator

1099 contractors have no unemployment insurance — your emergency fund IS your safety net. Find your recommended fund size based on employment type and income stability, then see exactly when you'll be fully funded.

Formula

target = monthly_expenses × recommended_months

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Savings Goal Calculator

Find out exactly when you'll reach your savings goal — and what monthly contribution gets you there faster. Shows time to goal, total contributions, and interest earned.

Formula

FV = PMT × ((1+r)^n − 1) / r + PV × (1+r)^n

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CD & High-Yield Savings Calculator

Calculate how much your CD or high-yield savings account will earn. Compare terms, rates, and compounding frequencies — see your exact interest earned, APY vs APR, and a month-by-month schedule.

Formula

FV = P × (1 + APR/n)^(n×t)

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Equity & Stock Options Calculator

Model the tax impact of ISO, NSO, and RSU equity grants. Compare sell-now vs hold-to-exit scenarios, calculate AMT spread for ISOs, and see your true net after federal, state, and capital gains taxes.

Formula

net = gain − (ordinary_tax + LTCG_tax)

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Business Loan Affordability Calculator

Calculate monthly payments, total interest, and whether you can actually afford a business loan. Shows DSCR (Debt Service Coverage Ratio) with lender thresholds, maximum affordable payment, and a 12-month amortization table.

Formula

DSCR = net_operating_income / annual_debt_service

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Financial Independence Number Calculator

Calculate your FI number at three expense tiers: essential-only, full lifestyle, and dream life. See years to each tier at your savings rate, your Coast FI number, and the monthly savings needed to retire by your target age.

Formula

FI number = annual_expenses ÷ 0.04

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Real Estate Investment Calculator

Evaluate rental property deals with cap rate, cash-on-cash return, monthly cash flow, the 1% rule check, and a 10-year equity projection. Full mortgage payment and operating expense breakdown included.

Formula

cash-on-cash = annual_cashflow / down_payment

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Contractor Retirement Catch-Up Calculator

Compare your current retirement savings pace vs an aggressive catch-up scenario. Projected balance at retirement, monthly income (4% SWR), milestone timeline, and Solo 401k contribution limits for self-employed contractors.

Formula

FV = PV×(1+r)^n + PMT×((1+r)^n − 1)/r

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Time Value of Money Calculator

Solve any TVM variable: present value, future value, payment, interest rate, or number of periods. Supports ordinary annuity and annuity-due with amortization schedule and sensitivity analysis.

Contractor Credit Score Impact Calculator

1099 contractors: see what lenders actually use as your income (net SE, not gross), calculate front-end and back-end DTI, get loan qualification likelihood, and credit improvement actions ranked by impact.

Working Capital Calculator

Know if your business has enough liquidity to cover short-term obligations. Essential for contractors and freelancers.

Formula

Working Capital = Current Assets − Current Liabilities

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Personal Inflation Calculator

Calculate your personal inflation rate based on your actual spending mix — housing, groceries, healthcare, and more. See how your cost-of-living increase compares to the official CPI and the salary raise you need just to break even.

Formula

personal_inflation = Σ(spending_weight × price_change)

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12-Month Cash Flow Forecast

Model a full year of cash flow as a freelancer or contractor. Separate invoices from collections, auto-reserve for taxes via set-aside %, add up to 5 one-time expenses, flag risk months below your safety buffer, and see year-end balance.

Formula

net = collections − (fixed + variable + taxSetAside + oneTime)

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HSA Contribution Optimizer

Calculate your 2024 HSA contribution limit, federal tax savings at your marginal rate, and 20-year investment growth. See exactly how the government subsidizes every dollar you put in the only triple-tax-free account.

Formula

tax_savings = contribution × marginal_rate

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Contractor Credit Score Impact

See how your credit score affects loan rates, APR, and total interest — with contractor-specific advice.

Formula

Monthly Payment = P × [r(1+r)^n / ((1+r)^n - 1)]

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Crypto Income Tax Calculator

Calculate SE tax on crypto received as payment and capital gains tax on crypto sales. LTCG/STCG rates, every IRS formula shown.

Inflation Calculator

Find out what any dollar amount is worth across time — past or future. Powered by CPI data from 1913–2024 with actual historical rates. See how inflation erodes purchasing power and what you need to earn to keep up.

Formula

adjusted = amount × ∏(1 + CPIᵧ/100)

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1099 Worker Tax Season Checklist

Interactive tax season checklist for freelancers and 1099 workers. Income documents (1099-NEC, 1099-K), deductible expenses, estimated tax payments, required forms (Schedule C, SE, 8829), and W-9/contractor records. Check off items, track progress %, copy as text.

Formula

progress = checked / total × 100%

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Year-End Tax Checklist

Interactive year-end tax checklist for self-employed workers and freelancers. Organized by deadline: Dec 31 action window (Solo 401k, §179 assets, mileage log), Jan 31 (1099-NEC, bank reconciliation), and April 15 (SEP-IRA, Schedule C, QBI deduction). Three-state items: checked / N/A / unchecked. localStorage persistence. Tax savings calculator for retirement, health insurance, and home office deductions.

Formula

taxSaved = (retirement + healthIns + homeOffice) × marginalRate

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Invoice Late Fee Calculator

Calculate late fees on overdue invoices. Choose flat fee, daily %, or monthly % with optional compounding. See days overdue, fees accrued, daily accrual rate, total owed, and 30/60/90-day projections. Includes 3 copy-paste contract language templates.

Formula

fee = invoice × rate × (days_past_due − grace)

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Invoice Due Date Calculator

Enter an invoice date and payment terms (Net 15/30/45/60) to get the exact due date, follow-up reminder date, and overdue status. Includes .ics calendar export with a 3-day reminder.

Formula

due = invoice_date + net_days

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Social Security Benefits Estimator

For freelancers and self-employed workers: estimate SS credits earned, AIME, PIA, and monthly benefit at 62/67/70. Shows break-even ages for claiming decisions and the impact of working more years. Includes credit eligibility tracker.

Formula

PIA = 90%(AIME≤$1,174) + 32%($1,174–$7,078) + 15%(above)

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Client Payment Terms Analyzer

What is net-60 actually costing you? Working capital tied up in AR, opportunity cost at your savings rate, invoice float count, and the annual value of switching to net-15 or net-30. Includes late-payer adjustment.

Formula

AR Float = Daily Revenue × Avg Days Outstanding

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Freelancer Annual Tax Summary

The flagship freelance tax overview. Enter your full year of 1099 income, expense categories (home office, mileage, software, equipment, meals, other), retirement contributions, health insurance, state, and filing status to see the complete tax waterfall: net SE income, SE tax, AGI, federal income tax with bracket breakdown, state income tax, total liability, quarterly payments, safe harbor, and net take-home.

Formula

gross → expenses → SE tax → AGI → fed → state → take-home

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HBTax: eBay Reseller P&L Calculator

Your 1099-K isn't your taxable income. Enter eBay gross sales, COGS, platform fees, and expenses — get your actual taxable profit, SE tax estimate, and the difference between what eBay reported and what you actually owe tax on.

Formula

taxable_profit = gross_sales − COGS − fees − expenses

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HBTax: Platform Fee Calculator

Compare selling fees across eBay, Etsy, Poshmark, Depop, Facebook Marketplace, and Mercari. Enter sale price, shipping, and item cost — see net proceeds and profit on all 6 platforms side by side with the winner highlighted.

Formula

net = sale_price − platform_fee − payment_fee

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HBTax: Reseller Tax Estimator

Multi-platform reseller tax calculator. Enter income per platform (eBay, Etsy, Poshmark, other), COGS, fees, filing status, and state — get taxable profit, SE tax, federal + state estimate, quarterly payment, and the set-aside percentage to save per sale.

Formula

SE_tax = profit × 0.9235 × 0.153

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FBA Product Research Scorer

Score Amazon FBA product opportunities across profitability, demand, and competition. Enter BSR, COGS, referral fee category, FBA size tier, and competing seller count — get net profit, ROI, monthly profit, and an overall Hot/Good/Maybe/Skip verdict.

Formula

net_profit = price − referral_fee − FBA_fee − COGS − inbound_shipping

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Multi-Marketplace Fee Comparison

Same item, 7 platforms — which one nets more? Compare selling fees across eBay, Amazon FBM, Etsy, Depop, Poshmark, Mercari, and Facebook Marketplace with 2024 fee structures. Ranked best to worst with winner badge.

Formula

net = sale_price − platform_fees − shipping_cost

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Dropshipping Profit Margin Calculator

Calculate true dropshipping net margin after supplier cost, shipping, payment processing, return rate, and optional ad spend. See break-even sale price and ROAS needed to be profitable before running paid traffic.

Formula

net_margin = (price − supplier − shipping − fees − returns − ads) / price

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HBTax: Reseller Inventory Tracker

Track what you paid for inventory, what you sold it for, and on which platform. Per-item COGS, platform fees, profit, margin, and days-to-sell. Export as CSV for your tax spreadsheet or CPA. Built so tax season takes 30 minutes, not 7 hours.

Formula

profit = net_proceeds − COGS

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HBTax: Reseller State Sales Tax Guide

eBay, Etsy, Poshmark, and Amazon handle sales tax for you in most states. See which platforms are marketplace facilitators, your economic nexus exposure by state, and whether you need to register anywhere.

Formula

nexus = f(platform_MF_status, home_state, annual_volume)

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HBTax: eBay Seller Fees Calculator

Calculate your exact eBay Final Value Fees by category, Top Rated Seller discount (10%), promoted listings cost, and true net profit. See the full fee stack before you list.

Formula

net_profit = price − FVF − promoted_fee − $0.30 − shipping − COGS

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LLC Tax Savings Calculator

Compare Sole Proprietorship, Single-Member LLC, and S-Corp election side by side. See exactly how much SE tax you save with an S-Corp, when the break-even is, and whether to elect now.

Formula

savings = solePropSETax − (salary × 15.3%) − accountingCost

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Am I an Employee or Independent Contractor?

Answer 11 questions to see how the IRS classifies your work arrangement. Covers behavioral control, financial control, and relationship type — plus the stricter ABC test used in CA, NJ, and MA.

Formula

behavioral + financial + relationship → risk level

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Gig Economy Tax Calculator

Calculate your 2024 gig platform taxes for Uber, Lyft, DoorDash, Instacart, Upwork, Fiverr, or TaskRabbit. Net profit, SE tax, quarterly estimated payments, mileage deduction, and 1099-K threshold — all in one place.

Formula

net profit = gross − fees − mileage − expenses

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Freelance Expense Category Finder

Type any freelance expense to instantly see the IRS deduction category, Schedule C line number, deductibility %, caveats, and IRC section. 40+ common expenses covered — software, home office, equipment, meals, travel, and more.

Quarterly Tax Planner — Full Year View

Plan all 4 quarters of estimated self-employment tax payments at once. Enter income and expenses per quarter, get cumulative YTD tax liability, safe harbor minimums, underpayment penalty risk, and the recommended payment for each quarter. Supports all 50 states.

Formula

recommended = max(safeHarbor, ytdBalance ÷ remainingQuarters)

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Compound Interest Visualizer

Student tool for ages 13-21. Interactive sliders for starting amount, monthly contribution, annual interest rate (1-15%), and years (1-40). SVG line chart shows compound growth vs saving-only side by side. Rule of 72 doubling time. Preset scenarios (first job paycheck, $25/week from age 16, birthday money). ShowMath walks through every formula including A = P(1 + r/n)^(nt). Outputs: final balance, total contributed, total interest earned (the wow number), interest multiplier.

Formula

A = P(1 + r/n)^(nt) + PMT × ((1 + r/n)^(nt) − 1) / (r/n)

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What Will My First Paycheck Actually Be?

Student tool for ages 16-21. Enter hourly wage and hours per week to see exactly where every dollar goes. Shows gross pay → federal income tax (2024 standard withholding) → Social Security (6.2%) → Medicare (1.45%) → state income tax → net take-home. Friendly explanations for each deduction. W-2 vs 1099 contractor comparison showing why contractors pay more. ShowMath walks through every step.

Formula

netPay = gross − federalTax − SS(6.2%) − Medicare(1.45%) − stateTax

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Freelancer Tax Deadline Calendar 2025-2026

Month-by-month tax deadline reference for self-employed workers. Covers Jan 2025 through Dec 2026: Q1-Q4 estimated taxes, 1099-NEC deadlines, S-Corp/Partnership returns, individual return deadlines (original + extension), SEP-IRA and Solo 401k contribution deadlines, and year-end deduction purchase cutoffs. Filter by entity type. Add any deadline to Google Calendar in one click. Countdown to next deadline.

Formula

nextDeadline = min(filteredDeadlines where date ≥ today)

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Writer & Journalist Tax Deduction Finder

Find every tax deduction available to freelance writers, authors, and journalists. Schedule C vs Schedule E royalty determination, home office (Form 8829), equipment (Section 179), research expenses, professional memberships, and SE tax with take-home calculator.

Formula

takeHome = grossIncome − deductions − seTax − federalTax

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Real Estate Agent Tax Calculator

Calculate real estate agent taxes after broker split. Standard mileage vs actual vehicle expenses comparison, MLS fees, E&O insurance, desk fees, association dues, signage, photography, open house expenses, marketing, CRM software, home office deduction, and full SE tax breakdown.

Formula

netProfit = (GCI − brokerSplit) − deductions

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Teacher & Educator Expense Deduction Calculator

Calculate the K-12 educator expense deduction: $300 per eligible teacher, up to $600 married filing jointly. Eligible classroom expense checklist, estimated federal + state tax savings, and SE tax calculation for tutoring and curriculum development side income.

Formula

deduction = min(classroomExpenses, $300) per eligible educator

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Musician & Artist Tax Calculator

Calculate taxes for musicians, artists, and performers. Covers performance fees, royalties, lesson income, and merch revenue. Includes SE tax, federal income tax, quarterly estimated payments, and IRC §183 hobby loss risk flag.

How Credit Scores Actually Work

See exactly how FICO scores are calculated — payment history, utilization, account age, and more. Simulate your score and explore what-if scenarios.

Formula

Score = Σ(factor × weight) + 300

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What Does Your Hourly Wage Actually Buy?

Translate your hourly rate into real take-home pay after taxes. See what your paycheck actually covers — and what things really cost in hours of work.

Formula

Net = Gross − FICA − Federal Tax − State Tax

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What Will Your Student Loan Really Cost You?

See the true cost of your student loan — total interest, monthly payment, and exactly how much you'll pay back vs. what you borrowed.

Formula

Payment = P×r×(1+r)^n / ((1+r)^n − 1)

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Savings Goal Calculator

Set up to 3 savings goals and see exactly how long it takes to reach each one. Compound interest, target date, total interest earned, and a 'what if I save more?' sensitivity table. Works for emergency funds, used cars, college costs, and house down payments.

What Inflation Is Doing to Your Money

See how inflation erodes purchasing power over time. Enter your salary or savings to see what it buys in today's dollars vs 5, 10, 20, or 30 years from now. Compare inflation vs HYSA (4.5%) vs S&P 500 (10%). Historical presets for 1970s, 2022 peak, and current 2024 CPI.

True Cost of Owning a Car Calculator

The sticker price is just the beginning. Calculate your real monthly cost (loan + insurance + fuel + maintenance + registration), 5-year total ownership cost, cost per mile, depreciation schedule, and net cost after resale. Includes buy vs lease comparison.

Debt Payoff Calculator

Compare the avalanche method (highest APR first) vs snowball method (lowest balance first) for paying off up to 5 debts. See total interest paid, months to payoff, payoff order, and a balance-over-time chart for each strategy.

Formula

avalanche = extra → highest APR · snowball = extra → lowest balance

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Side Hustle Tax Calculator

Calculate the exact additional tax on side hustle income when you also have a W-2 job. Side income stacks on top of your salary and is taxed at your marginal rate — plus 15.3% self-employment tax. Shows SE tax, additional federal tax, state tax, effective rate, and quarterly estimate.

Formula

SE tax (15.3%) + marginal federal rate on stacked income + state tax

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Amazon Seller Fee Calculator

Calculate your true Amazon profit before listing. Enter product category, sale price, weight, dimensions, and COGS to get a full FBA or FBM fee breakdown — referral fee, fulfillment fee, storage fee — plus net profit per unit, monthly profit, annual profit, margin %, and breakeven price.

Formula

net profit = sale price − referral fee − FBA fee − storage fee − COGS

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Business Asset Depreciation Calculator

Model four depreciation methods for any business asset: MACRS (IRS standard half-year convention), Straight-Line, Section 179 full first-year expensing (2024 limit $1.22M), and 60% Bonus Depreciation. Enter asset cost, class (5-yr, 7-yr, 27.5-yr, 39-yr), business use %, and marginal rate to get a year-by-year deduction schedule, total tax savings, and NPV at 7%.

Formula

tax savings = Σ(yearly deduction × marginal rate) discounted at 7%

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50/30/20 Budget Builder

Build your budget with the 50/30/20 rule. Enter your income and expenses — get real-time feedback on each spending bucket with colored progress bars and gap analysis.

Formula

50% Needs + 30% Wants + 20% Savings

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Income Tax Brackets Visualizer

See exactly how the 2024 federal tax brackets work. Enter your income and filing status to see how much falls in each bracket, total tax, effective (average) rate vs marginal rate, and why a raise never makes you poorer. Stacked bar chart + bracket table.

Formula

effective rate = total tax ÷ gross income · marginal rate = top bracket only

181

Net Worth Calculator

Assets minus liabilities — your complete financial snapshot. Track progress over time with localStorage snapshots and benchmark against your age group.

Formula

Net Worth = Total Assets − Total Liabilities

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Financial Independence: How Close Are You?

Calculate your FI number (expenses × 25), years to financial independence, and see exactly how dramatically your savings rate shortens the timeline.

Formula

FI Number = Annual Expenses × 25

185

Amazon FBA Profitability Calculator

Full FBA P&L: referral fee, fulfillment fee, storage, PPC, returns — net margin, ROI, break-even price, and FBA vs FBM comparison.

Business Loan Calculator

Monthly payment, total interest, true APR (fees included), amortization schedule, and ROI analysis — is this loan worth it?

Formula

PMT = P × r / (1 − (1+r)^−n)

187

Charitable Giving Tax Deduction Calculator

Cash donations, appreciated stock, DAF bunching strategy — see your true after-tax cost of giving and whether itemizing beats the standard deduction.

W-4 Tax Withholding Optimizer

Stop giving the IRS an interest-free loan. Enter your income, deductions, credits, and current withholding to see if you're over- or under-withholding, and get exact W-4 Step 3 and Step 4(c) adjustments to land within $500 of $0 owed at filing.

Stock Market Basics: What Is a Share Actually Worth?

Understand P/E ratios, earnings yield, market cap, and dollar-cost averaging with interactive simulators. See why index funds beat most active managers.

Formula

P/E = Share Price ÷ Earnings Per Share

190

Freelance Revenue Forecast

Project your freelance revenue month by month with growth rates, seasonality toggles, best/base/worst scenarios, and gap analysis to your annual goal.

Formula

Projected = Base × (1+g)^m × Seasonality

191

Print on Demand Profit Calculator (Printful/Printify)

Calculate real profit margins for Printful and Printify products sold on Etsy or Shopify. Shows profit per unit, margin %, monthly profit, break-even price, and effective hourly rate. Includes full fee breakdown for all platform charges.

Formula

profit = price − base cost − platform fees · break-even = (base + fixed fees) / (1 − pct fees)

194

Crypto Portfolio Tax Calculator

Calculate tax on your full crypto portfolio. Short-term vs long-term capital gains, staking income (Rev. Rul. 2023-14), mining SE tax, and loss harvesting opportunities. Key highlight: crypto is NOT subject to the wash sale rule.

Formula

STCG at marginal rate · LTCG at 0/15/20% · staking = ordinary income · mining + SE tax

195

Rental Property ROI Calculator

Calculate the real ROI of a rental property: monthly cash flow, cap rate, cash-on-cash return, gross rent multiplier. Includes 3% and 5% appreciation scenarios with 5/10/30-year equity projections and a full monthly expense breakdown.

Formula

cash flow = rent − vacancy − expenses − mortgage · cap rate = NOI ÷ price · CoC = annual CF ÷ invested

196

Freelancer Retirement Gap Calculator

How far behind are you on retirement? Uses Fidelity benchmarks, projects your balance to retirement, calculates your FI number (expenses × 25), estimates Social Security income, and tells you exactly how much more to save monthly to close the gap.

Formula

FV = PV×(1+r)^n + PMT×[(1+r)^n−1]/r · FI number = expenses×25 · gap = FI−projected

197

Subscription Audit Calculator

Add up all your subscriptions, flag the ones you barely use, and see what that dead weight would be worth invested over 10, 20, and 30 years.

Formula

FV = PMT × ((1+r)^n − 1) / r

198

HSA Tax Triple Benefit Calculator

HSAs are the most tax-advantaged account most people never maximize. See immediate tax savings (contributions reduce AGI + save FICA), projected tax-free growth, the Stealth IRA strategy, and your total tax benefit vs a taxable account over your career.

Tax Loss Harvesting Calculator

Turn investment losses into tax savings. See IRS netting rules applied (STCL vs STCG first, then LTCL vs LTCG, then cross-netting), total tax saved, ordinary income deduction up to $3,000 (IRC §1211), carry-forward loss, and whether harvesting is worth the transaction costs.

Tax Extension Calculator

Filed Form 4868? An extension delays your filing deadline — not your payment. Calculate your April 15 balance due, 0.5%/month failure-to-pay penalty, daily IRS interest, and total cost of waiting until October 15.

Formula

Cost = Balance Due × (0.5%/mo × Months + FFR+3%/365 × Days)

205

Passive Income Calculator

How much capital do you need to replace your income? Build your income mix across dividends, REITs, bonds, and HYSA — see blended yield, capital needed, years to target, and a 20-year projection.

Formula

capital needed = annual income ÷ blended yield

206

Social Security Claiming Strategy Calculator

When should you claim Social Security? See your break-even age, cumulative lifetime benefits at 62 vs 67 vs 70, and the optimal claiming age based on your life expectancy. Spousal benefit included.

Formula

benefit at 70 = FRA × 1.24 · benefit at 62 = FRA × 0.70

207

How Interest Rates Affect Everything

See how Fed rate changes ripple through your mortgage, car loan, savings account, and credit card. Enter your actual balances and simulate a rate cut or hike to see your net monthly impact.

Formula

net impact = ARM savings + card savings − savings yield loss

208

Opportunity Cost Calculator

See the true cost of everyday spending habits. That daily $5 coffee is $170,000 in 30 years if invested at 7%. Calculate what any habit costs in foregone investment returns — with year-by-year growth table.

Formula

FV = annual cost × [(1+r)^n − 1] / r

209

GDP & Inflation: What the Economy Means for Your Wallet

Connect macro economics to your finances. Learn real vs nominal GDP, track CPI inflation 2015–2024, calculate your personal inflation rate based on your spending mix, and find your real return with the Fisher equation.

Formula

real return = (1+nominal)/(1+inflation) − 1

215

Time Value of Money Calculator

Future value, present value, required return, and required time — with annuity mode, inflation adjustment via Fisher equation, and year-by-year compound schedule.

Formula

FV = PV x (1+r)^n

216

What's Your Money Personality? (Quiz)

10-question quiz reveals your financial archetype: Builder, Spender, Avoider, or Protector — with personalized strengths, blind spots, and 3 action steps.

Are You Living Paycheck to Paycheck?

Enter your monthly take-home, fixed and variable expenses, and savings to get a paycheck-to-paycheck score, 50/30/20 budget gap analysis, and a ranked action plan.

Formula

surplus = take-home − expenses − savings

218

The True Cost of Debt Calculator

See the real cost of minimum payments in total interest paid, years to payoff, and how much you save by doubling your payment. Works for credit cards, car loans, mortgages, student loans.

Formula

months = −ln(1 − r×B÷P) ÷ ln(1+r)

219

How AI Actually Works

Visual explainer of neural networks, training, tokenization, and the perceptron math behind AI. Interactive sliders show how changing weights shifts output probability.

Exponential Growth Visualizer

See why small growth rates become huge over time. Visualize compound interest, viral spread, Moore's Law, and bacteria doubling on the same chart with linear comparison.

Probability & Statistics Visualizer

Interactive visualizer of core probability concepts: coin flip law of large numbers, normal distribution bell curve, expected value, and Bayes' theorem with medical test example.

1099 vs W-2 Equivalence Calculator

Convert between 1099 contractor rates and W-2 salaries. See the SE tax gap, employer payroll tax, health insurance, retirement match, and PTO value — and the exact premium a contractor must charge to break even.

Formula

1099 needed = W-2 total comp ÷ (1 − SE rate)

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Gig Income Tax Burden Calculator

Calculate the full tax picture on gig / 1099 income: SE tax, federal brackets, state tax, mileage deduction, home office, and quarterly estimated payments — all in one tool.