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Money & finance

Debt payoff calculator

Debt payoff calculator: enter your values and get an instant free result.

Your result

Complete the fields and calculate.

Calculation method and formula

r = Interest rate [% p.a.] ÷ 1200; B(next month) = maximum(0, B × (1 + r) − Regular monthly payment − Extra monthly payment)

Understand the inputs

Debt
Use a measured value or your own assumption.
Interest rate
Unit: % p.a.. Use a measured value or your own assumption.
Regular monthly payment
Use a measured value or your own assumption.
Extra monthly payment
Use a measured value or your own assumption.

Assumptions and limitations

Repayment is simulated month by month at a constant rate and payment. New spending, fees and variable payments are excluded. A payment below monthly interest cannot repay the balance.

The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation.

Worked example

Illustrative values. Replace them with your own inputs for your calculation.

Debt
12000
Interest rate
8 % p.a.
Regular monthly payment
300
Extra monthly payment
50
Example result40 months

Interest until payoff: 1,669.76.

Model revision: October 17, 2026 · How CleverCalc works

FAQ

Frequently asked questions

How does Debt payoff calculator work?+

r = Interest rate [% p.a.] ÷ 1200; B(next month) = maximum(0, B × (1 + r) − Regular monthly payment − Extra monthly payment). Repayment is simulated month by month at a constant rate and payment. New spending, fees and variable payments are excluded. A payment below monthly interest cannot repay the balance.

What assumptions should I consider for this result?+

Repayment is simulated month by month at a constant rate and payment. New spending, fees and variable payments are excluded. A payment below monthly interest cannot repay the balance. The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation.

How accurate is the result?+

The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation. Prices, measurements and model assumptions determine how well the result represents your situation.

Is this calculator free?+

Yes. Calculations and PDF export work without an account or registration.

What happens to my inputs?+

Calculations run in your browser. Results are saved locally only when you add them to My results; favourites and history are also local. Shared links contain your values. The currency tool requests the selected currencies from its rate provider without sending your amount.

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