Finance
Debt Payoff Calculator
Calculate how long it will take to pay off your debt and how much interest you'll pay.
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Monthly payment must be higher than monthly interest charges to pay off the debt.
Finance
Calculate how long it will take to pay off your debt and how much interest you'll pay.
Monthly payment must be higher than monthly interest charges to pay off the debt.
A debt payoff calculator is a tool that estimates the time required to fully repay a loan or credit card balance. It combines your debt amount, annual interest rate (APR), and fixed monthly payment to compute the total number of months until you're debt-free and the total interest charged over the life of the loan. Unlike a simple division, it accounts for compound interest—each month, interest is calculated on the remaining balance, making the math more realistic than just dividing balance by payment.
The calculator uses the debt payoff formula, which solves for the number of months using logarithms. It applies your monthly interest rate (APR ÷ 12 ÷ 100) to the remaining balance each month, deducts your fixed payment, and repeats until the balance reaches zero. It also tallies total interest by summing all interest charges across all months.
Months = -ln(1 - (Balance × Monthly Rate) ÷ Payment) ÷ ln(1 + Monthly Rate)
where Monthly Rate = (APR ÷ 100) ÷ 12
Total Interest = (Payment × Months) - BalanceThe formula solves the balance-reduction equation backwards: it finds how many payment cycles are needed to reduce the balance to zero at a given interest rate. Monthly rate is APR divided by 12 because interest compounds monthly. Total interest is whatever you pay beyond the original balance.
| Input | Result | Notes |
|---|---|---|
| Balance: $15,000 | APR: 15% | Monthly payment: $400 | Approximately 42 months (3 years 6 months) to payoff | You'll pay roughly $1,810 in interest, so total out-of-pocket is $16,810 |
| Balance: $5,000 | APR: 22% | Monthly payment: $200 | Approximately 27 months (2 years 3 months) to payoff | Higher interest rate means more of each payment goes to interest early on |
| Balance: $25,000 | APR: 6% | Monthly payment: $500 | Approximately 52 months (4 years 4 months) to payoff | Lower interest rate and higher payment both accelerate payoff; total interest roughly $1,000 |
Your debt will grow instead of shrink. For example, if your balance is $5,000 at 30% APR, monthly interest is ~$125; if you pay only $100, you owe more next month. You must pay at least the interest charge each month, plus extra toward principal, to ever pay off the debt.
Yes. Banks and credit card companies allow you to increase your payment anytime. If you increase your payment, recalculate your payoff timeline to see the new date. Many borrowers start with a lower payment and increase it once they get a raise or pay off another debt.
Small differences occur due to rounding, payment dates, or monthly vs. daily compounding. Banks may also charge fees or apply extra charges. This calculator assumes fixed rates and simple monthly compounding; check your statement for the exact terms.
Increase your monthly payment as much as possible. Even $50 extra per month can save months of payments and hundreds in interest. Some people use the 'avalanche method' (pay minimums on all debts, put extra toward the highest APR) or 'snowball method' (pay off smallest balance first for psychological wins).
No. Paying off debt early improves your credit score because it lowers your credit utilization ratio and shows you're responsible. There's no penalty for early payoff on most loans (though some old mortgages had prepayment penalties—check your agreement).
Experiment with the calculator. Try different payment amounts to find the timeline that fits your budget. Remember: any payment above the interest charge moves you toward debt freedom.