Debt Payoff Calculator
Estimate payoff time and interest for a debt using a fixed monthly payment.
Educational estimate only. This is not financial, investment, tax, legal or lending advice, a quote or a guarantee. Read the disclaimer.
Your inputs
How this calculator works
Each month adds interest at the annual percentage ÷ 100 ÷ 12, then subtracts the fixed payment. The final payment is reduced to the remaining balance plus interest. No new borrowing, fees, daily accrual or changing rates are included. Payments that do not cover interest cannot repay the balance. Estimates beyond 1,200 months are flagged rather than presented as a completed payoff; a residual of one cent or less ends the simulation. This is a single-debt model and does not optimize repayment across multiple debts.
Dollar results are in USD and generally rounded to the nearest whole dollar; salary equivalents and percentage outputs use two decimal places. Calculations retain JavaScript floating-point precision between steps rather than rounding every payment to cents. Displayed components may not sum exactly to displayed totals. Payoff times use whole monthly payment periods. Defaults are examples, not current rates or recommendations.
Full methodology · About the publisher and corrections
Content and calculation checks: October 12, 2026. Educational estimates; no independent professional certification is claimed.
Worked example: $20,000 debt at 10%
For a $20,000 balance at 10% interest with a fixed $500 monthly payment, the model estimates payoff in about 49 months. Total payments are about $24,429, including roughly $4,429 in interest.
The calculator models one balance and one fixed rate. It does not choose between avalanche, snowball or consolidation strategies.
Practical guide
Turn the result into a payoff plan
- Use the payment you can realistically sustain every month.
- Test an extra $25, $50 or $100 to see the incremental benefit.
- If you have multiple debts, list each rate and minimum payment before deciding which balance to prioritize.
- Verify whether your actual debt uses daily interest, variable rates or fees.
How to use the result
Change one assumption at a time to compare scenarios. For example, test a lower rate, larger contribution, different term or extra payment. This makes the calculator most useful as a decision-support tool rather than a single-number answer.
Important financial decisions can depend on taxes, fees, eligibility rules, lender policies, market returns and personal circumstances that this simplified calculator does not capture.
Frequently asked questions
Is this debt payoff calculator free?
Yes. SumStride calculators are free to use and do not require an account.
Are the results exact?
No. Results are estimates based on the values you enter and the assumptions described on this page. Real-world fees, taxes, rates, policies and timing can differ.
Does SumStride save my inputs?
No account is required. The calculator runs in your browser; SumStride does not need your entered values to perform the calculation.