Debt Payoff Calculator
Estimate how long it takes to pay off a balance with monthly and extra payments, plus total interest paid.
Guide
What is a debt payoff estimate?
A debt payoff estimate shows how many monthly payments are needed to clear a balance when you pay a fixed amount each month, optionally with an extra payment. Each month, interest accrues on the remaining balance before principal is reduced.
Formula
Monthly interest = Remaining balance × (Annual rate ÷ 100 ÷ 12). Principal reduction = Total monthly payment − Monthly interest. The schedule repeats until the remaining balance reaches zero. At a zero rate, months to payoff = Balance ÷ Total monthly payment.
Worked example
A 1,200 balance at 0% interest with a 100 monthly payment is paid off in 12 months with no interest. Adding extra payments shortens the payoff period and reduces total interest when the rate is above zero.
Assumptions and limitations
The Calculator assumes a fixed annual rate, fixed monthly payment, and fixed extra payment with no new charges, fees, or missed payments. Total monthly payment must exceed the first month's interest or the balance would not decrease.
Common questions
How is this different from the Loan Payment Calculator?
The Loan Payment Calculator finds the payment for a fixed term. This Tool finds how long payoff takes for payments you enter. Are extra payments applied every month? Yes. Extra payment is added to the monthly payment on each simulated month. What happens at 0% interest? Each payment reduces principal directly with no interest charge.
Methodology
The Calculator simulates month-by-month balances with decimal arithmetic, applies a final partial payment when needed, and rounds only displayed totals.