Loan Payoff Calculator

How extra payments save you money

Every extra dollar you pay toward a loan goes straight to reducing your principal balance — it isn't split between principal and interest like your regular payment is. A smaller principal balance means less interest accrues the following month, which means more of your next regular payment also goes to principal. This compounding effect is why even modest extra payments (an extra $50-100/month) can shave years off a loan and save meaningful interest, especially early in the loan term when the balance — and therefore the interest accruing on it — is at its highest.

Which loans is this calculator for?

This is a general-purpose amortizing loan calculator, so it works for:

• Auto loans — typically 3-7 year terms, fixed rate.
• Personal loans — typically 2-7 year terms, used for debt consolidation, home improvement, or other expenses.
• Student loans — federal and private student loans with a fixed rate amortize the same way (though federal loans have their own income-driven repayment options this calculator doesn't model — see the FAQ below).

For a mortgage specifically — with property tax, insurance, and PMI — use the mortgage calculator instead.

Frequently asked questions

Will my lender automatically apply extra payments to principal?

Not always — this depends on your loan servicer. Many lenders apply extra amounts to your next scheduled payment by default rather than directly reducing principal, unless you specifically mark the extra amount as "additional principal payment." Always confirm with your loan servicer that extra payments are being applied the way you intend, or you won't see the payoff acceleration this calculator shows.

Are there prepayment penalties?

Some loans — particularly certain personal loans and a small number of auto loans — charge a prepayment penalty for paying off the loan early or making large extra payments. Check your loan agreement before making large extra payments. Most mortgages, federal student loans, and modern auto loans do not have prepayment penalties, but it varies.

Does this model income-driven student loan repayment?

No. Federal student loans have income-driven repayment (IDR) plans where your payment is based on income rather than a fixed amortization schedule, and some plans include forgiveness after a set number of years. This calculator assumes a standard fixed-rate, fixed-term amortizing loan — it does not model IDR plans, forgiveness programs, or interest subsidies. If you're on or considering an IDR plan, use your loan servicer's tools or the Department of Education's official calculators instead.

Is my loan information uploaded anywhere?

No. Every calculation happens locally in your browser using JavaScript. Your loan balance, rate, and payment amounts are never sent to a server.