Debt Payoff Calculator
Find how long one fixed-rate debt may take to repay and see how an extra monthly payment changes the estimate.
Quick answer
Enter one balance, its APR and your monthly payment. The calculator simulates each month, applying interest before subtracting the payment.
Formula used
Monthly interest = current balance × APR ÷ 12. New balance = current balance + monthly interest − total payment.
Worked example
An extra payment reduces principal sooner, so later interest is calculated on a smaller balance. The result compares your entered total payment with the required payment alone.
How to interpret the result
This assumes a fixed APR, no new charges, no fees and one payment per month. Lender calculations and daily interest can differ.
Sources and methodology
Investor.gov compound interest calculator · Consumer Financial Protection Bureau: saving. Sources explain general concepts; ToolGemini calculations use only the values you enter and the formula shown above.
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Browse money calculators · Savings goal calculator · Compound interest calculator
Frequently asked questions
Why does the calculator say the payment is too low?
A payment that does not exceed the first month of interest will not reduce the balance under these assumptions.
Does an extra payment always reduce interest?
When it is applied directly to principal without a penalty, paying earlier generally reduces later interest. Confirm how your lender applies extra payments.
Can I combine multiple debts?
Use one debt at a time. Different balances and APRs need a snowball or avalanche calculator with separate rows.