Loan Payoff Calculator

How this estimate works

The calculator applies your monthly interest rate to the current balance each month, adds that interest, then subtracts your payment — repeating until the balance reaches zero. It compares two scenarios side by side: your required payment alone, and your required payment plus the extra amount you enter, so you can see exactly how much time and interest the extra payment saves.

Frequently asked questions

Does the extra payment go straight to principal?

In this calculator, yes — it assumes every dollar of your extra payment reduces the balance rather than being applied to future interest. Some lenders apply extra payments differently by default, so confirm with your servicer that extra payments reduce principal rather than just prepaying your next due date.

Why does a small extra payment save so much interest?

Because it shrinks the balance that next month's interest is calculated on, and that saving compounds every month after. A modest extra payment early in a long loan can save disproportionately more than the same amount paid later.

What if my payment doesn't cover the interest?

The calculator flags this — if your payment is at or below the interest charged each month, the balance never shrinks and payoff time is undefined; you'd need a higher payment or a lower rate for the loan to actually pay down.