Debt payoff time and interest.. Debt Payoff Calculator is a free online tool from the ToolsRift Finance & Health Calculators collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Enter your outstanding balance, annual interest rate and monthly payment. The calculator shows payoff time, total interest and a month-by-month schedule.
Each month interest is charged on the outstanding balance, your payment covers that interest first, and the rest reduces principal until the balance reaches zero.
Increase your monthly payment or make lump-sum prepayments. Because interest is charged on the balance, extra principal payments cut both time and total interest.
If your monthly payment does not cover the monthly interest, the balance never falls. The calculator flags when a payment is insufficient to make progress.