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//// Financial · Debt

The True Cost of Debt Calculator

See exactly how much your debt costs in total interest, how long minimum payments drag on, and the dramatic savings from doubling up. Eye-opening math shown.

401(k) Limit 2024$23,000
Roth IRA Limit$7,000
S&P 500 Avg Return~10%/yr

“Paying the minimum on a $5,000 credit card at 24% APR takes 22 years and costs $8,000 in interest.”

This is how the math works. Now here's how to beat it.

Debt Type

Debt Details

$
%
$

Monthly Interest Charge

$100

accruing right now

Daily Interest Charge

$3.29

while you sleep

Payment Scenarios

Minimum payment only

Monthly Payment

$100

Payoff Time

Never

Total Interest

Never

Total Paid

Never

Double minimum

Best move

Monthly Payment

$200

Payoff Time

3 yr

Total Interest

$2,200

Total Paid

$7,200

Saves Never in interest · 11952 months faster

+$50/month

Monthly Payment

$150

Payoff Time

4 yr 8 mo

Total Interest

$3,400

Total Paid

$8,400

Saves Never in interest · 11932 months faster

1

Loan Balance

= $5,000

The outstanding principal you owe.

2

Annual Percentage Rate (APR)

= 24%

The annual cost of borrowing, expressed as a percentage of the balance.

3

Monthly Interest Rate

APR ÷ 12

24% ÷ 12

= 2.0000%

The rate applied to your balance each month.

4

Monthly Interest Charge

Balance × Monthly Rate

$5,000 × 0.020000

= $100

How much of your minimum payment goes to interest alone each month.

5

Daily Interest Charge

Balance × (APR ÷ 365)

$5,000 × 0.000658

= $3.29/day

This is what you pay just to hold the balance — every single day.

6

Months to Payoff (Minimum Only)

−ln(1 − r × Balance ÷ Payment) ÷ ln(1 + r)

= Never

The standard amortization formula shows exactly how long minimum payments drag on.

Standard loan amortization formula

7

Total Interest — Minimum Payment

Payment × Months − Balance

$100 × 11988 − $5,000

= Never

You pay Infinity% of the original balance in interest alone.

8

Interest Saved — Doubling Payment

Interest(min) − Interest(double)

Never − $2,200

= Never

Doubling your payment is one of the most powerful moves you can make.

#ShowYourWork

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