Number Loan Calculator
Most loan calculators only solve for the payment. This one solves for whichever number you are missing — payment, amount, term or rate — and shows what extra payments do to your payoff date.
How it works
The loan payment formula is M = P × r(1+r)n / ((1+r)n − 1) with P the amount, r the monthly rate and n the number of payments. Solving for the amount or term rearranges the same formula; solving for the rate is done by testing rates until the payment matches yours exactly. Extra payments are applied to principal every month, which shortens the loan and cuts total interest — the table shows both versions side by side.
Frequently asked questions
How do I find the interest rate on my loan?
Choose "Interest rate" under Solve for, enter the loan amount, term and the monthly payment from your statement, and the calculator backs out the rate that produces that payment.
How much do extra payments really save?
A lot, because every extra dollar goes straight to principal. On a $30,000, 6%, 5-year loan, an extra $100 a month pays the loan off about 10 months early and saves roughly $500 of interest — try it above.
What is the difference between APR and interest rate?
The interest rate drives the monthly payment. APR folds in most lender fees as well, so APR is the better number for comparing two loan offers. This calculator uses the interest rate.
Can this calculator handle a 0% loan?
Yes. With a 0% rate the payment is simply the amount divided by the number of months, and total interest is $0.
🗓️ Want the month-by-month picture?
The Amortization Calculator lays out every payment — principal, interest and balance — for the whole loan.