Debt payoff with extra payments
Debt payoff with extra payments: use loan principal, nominal annual interest rate, number of monthly payments. Review the formula, worked example and calculation steps.
Inputs
Use the units shownEnter your values and select Calculate.
Formula & explanation
Variables & units
- Loan principal
- currency · minimum 0.01, maximum 1000000000000
- Nominal annual interest rate
- % · minimum 0, maximum 100
- Number of monthly payments
- months · minimum 1, maximum 600
- Extra principal each month
- currency · minimum 0, maximum 1000000000000
Worked example
At zero interest, 1,200 over 12 months plus 100 extra monthly is repaid in 6 months.
Assumptions
Fixed nominal annual rate divided by 12; equal end-of-month payments. Excludes fees, insurance, taxes, variable rates and lender rounding. Extra payments are applied after the period’s interest. No prepayment penalties.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
Use the default input values to find the answer. The reset icon restores those values.
Calculated on your device. Your latest 100 calculations stay in this browser.