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Financial calculator

Debt Payoff Calculator

Estimate how long a debt takes to repay, how much interest it costs and how extra monthly payments can change the payoff path.

Use the contractual APR and required monthly payment. This estimate assumes fixed rate, monthly compounding and no new borrowing.

Method

The calculator simulates the balance month by month. Each month, interest is added from APR / 12 and the entered payment reduces the balance. Extra monthly and one-time payments reduce principal in this simplified model.

Example

A $10,000 balance at 12% APR with a $350 monthly payment takes about 34 months to repay and costs roughly $1,700 in interest in this simplified model.

Common mistakes

Do not keep adding new charges if the goal is payoff. New borrowing can erase the effect of extra payments.

Limitations

Real debts can include variable rates, late fees, promotional rates, prepayment rules or changing minimum payments. This page is an educational estimate, not a lender payoff quote.

References

Last reviewed: 2026-05-16

Before relying on this result

Use this calculator together with the formula, assumptions, limitations and examples on the page. If the topic involves health, tax, lending, investment, legal, safety or current-rate decisions, treat the number as an estimate and check the relevant primary source or professional guidance.

Calculator metadata last reviewed: 2026-05-14.