Loan Calculator
This loan calculator works out the monthly payment on any fixed-rate loan, plus the total interest and the total cost. Enter the amount, the interest rate, and the term, and you'll see the payment right away, with a full amortization schedule. Add an extra monthly payment and it'll show how much interest you save and how much sooner the loan's paid off.
- Monthly payment
- Total interest
- Amortization schedule
- Extra-payment savings
- Years or months
Last updated June 16, 2026 Works for personal, auto, and student loans Reviewed by the Calcowa finance team
Enter a loan amount, rate, and term above 0.
Works for any fixed-rate loan. Estimates for planning, not a loan offer.
M = P × r(1+r)ⁿ ÷ ((1+r)ⁿ − 1)
How is a loan payment calculated?
A fixed-rate loan is paid back in equal monthly payments, each one part interest and part principal. The payment depends on three things: how much you borrow, the interest rate, and how long you have to repay. The formula spreads the loan evenly across the term so the balance reaches zero on the last payment. A longer term lowers the monthly payment but raises the total interest, since you're borrowing for longer. That's the trade-off, and the calculator shows both sides of it.
Working out the payment
Here's the method the calculator runs. It's the same for a $25,000 loan at 7.5% over 5 years:
- 1
Set the monthly rateDivide the yearly rate by 12: 7.5% ÷ 12 is 0.625% a month.
- 2
Count the paymentsMultiply the years by 12: a 5-year loan has 60 monthly payments.
- 3
Apply the formulaM = P × r(1+r)ⁿ ÷ ((1+r)ⁿ − 1) gives a payment of about $501 a month.
- 4
Add it upAcross 60 payments that's about $30,054, so roughly $5,054 of it is interest.
Loan amortization schedule
This schedule shows how each year splits between interest and principal, and how the balance falls to zero. Early payments lean toward interest; later ones pay down more principal. It'll update with your numbers, so you'll see the effect of any extra payment right away.
| Year | Interest | Principal | Balance |
|---|
How extra payments save interest
Every dollar you pay above the scheduled amount goes straight to the principal, not interest. That shrinks the balance early, and that's where the saving comes from: since interest is charged on the balance, it lowers every future interest charge too. The effect compounds, so a modest extra payment each month can knock months or years off the term and save a real chunk of interest. Type an amount in the extra-payment box above and you'll see the new payoff date and the interest saved. It's one of the simplest ways to pay less, and you're fully in control of the pace. For a home loan, the mortgage calculator does the same with taxes and insurance, and the compound interest calculator shows the saving side.
Frequently asked questions
Is this loan calculator free?
Yes, it's free and runs in your browser with no sign-up. The figures are estimates to help you plan, so your lender's exact numbers may differ a little with fees and rounding.
The monthly payment uses the loan amount, the monthly interest rate, and the number of payments. The formula is M = P × r(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the loan, r is the yearly rate divided by 12, and n is the term in months. This loan calculator runs it for you, so you don't work the powers by hand, and it shows the total interest and the full schedule.
Amortization is paying a loan off in equal payments, where each one covers the interest first and then chips away at the balance. Early payments are mostly interest; later ones are mostly principal. The schedule above shows that shift year by year, so you'll see the balance fall and the interest shrink over time.
Add a little extra to each payment. Because the extra goes straight to principal, it cuts the balance early and saves interest on every month that follows. Enter an extra monthly amount above and you'll see the new payoff date and how much interest you save. Even a small amount can trim months off the term.
The loan is the amount you borrow; the interest rate is the yearly cost of borrowing it, as a percent. A higher rate means more of each payment goes to interest rather than principal, so the loan costs more overall even if the monthly payment doesn't look very different. Try changing the rate above to see the total interest move.
Yes. The math is the same for any fixed-rate installment loan, whether it's a personal loan, car loan, or student loan. Just enter the amount, the rate, and the term in years or months. For a home loan with taxes and insurance, the mortgage calculator adds those extra pieces.
The interest rate is the cost of borrowing the principal, while APR also folds in certain fees, so it's usually a touch higher and gives a fuller picture of the yearly cost. This calculator uses the interest rate for the payment math. If your loan quotes an APR with no extra fees, they're the same.
Related calculators
More tools for borrowing and saving.
Car payment with tax and trade-in.
Mortgage calculatorHome loans with taxes and PMI.
Compound interestSee how savings grow.
Taking out a loan?
Run your numbers above, or browse the full finance hub.