Enter your loan balance, APR, and monthly payment to see how long until it’s gone and what it costs in interest. Add an extra monthly payment and watch the payoff date move up — plus exactly how many months and dollars the extra saves you. Updated live as you type.
How it works
The calculator simulates real month-by-month amortization: each month, interest accrues on the remaining balance at APR ÷ 12, and your payment covers that interest first, with the rest retiring principal. Because interest compounds on what you still owe, small extra payments early are worth far more than the same dollars later — that’s the whole trick of the “extra payment” field. If your payment doesn’t cover the monthly interest, the tool tells you plainly instead of showing a fantasy payoff date.
Everyday examples
Credit card debt: a $10,000 balance at 24% APR paying $100/month never goes away — the monthly interest alone is $200. At $500/month it’s gone in 23 payments costing $1,213 in interest. Car loan: a $25,000 balance at 7% with $485 payments clears in about 61 payments; adding $100 gets you there 9 payments sooner and saves roughly $700 in interest. Mortgage: see our mortgage calculator for full amortization schedules — this tool is tuned for payoff questions on cards, auto, and personal loans.
The payoff date assumes you keep paying exactly this amount every month, starting now. Real life varies — but the shape of the savings doesn’t. Built in-house in plain JavaScript — no widgets, no tracking, nothing you type leaves your device.