How do I calculate a monthly loan payment?
For a fixed-rate loan the monthly payment is P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the amount borrowed, r is the yearly rate divided by 12 and n is the number of months. For example, 20,000 at 7.5% over 5 years is 400.76 a month with 4,045.54 in total interest. FixDoks's Loan Calculator shows this instantly, with a full schedule.
Loan Calculator at a glance
| Inputs | Loan amount, rate, term, optional extra payment |
|---|---|
| Output | Monthly payment, total interest, schedule, payoff date |
| Processing | In your browser; your files are not uploaded |
| Price | Free |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use Loan Calculator
- Pick a preset such as Car loan or enter your own loan amount.
- Enter the yearly interest rate (APR) and the term in years or months.
- Optionally add an extra payment each month to see how much sooner the loan closes.
- Read the monthly payment and total interest, and download the schedule as CSV if you need it.
How loan payments work
Personal loans, car loans and most student loans are amortizing loans: you pay the same amount every month, and each payment covers that month's interest first, then reduces the balance. Because the balance shrinks, the interest part gets smaller every month and the principal part gets bigger.
Worked example
You borrow 20,000 at 7.5% a year for 5 years (60 months).
- Monthly payment: 400.76
- Total interest: 4,045.54
- Total repaid: 24,045.54
Paying extra
An extra payment goes straight to the principal, so every later month has less interest. Enter an amount in the extra payment box and the calculator shows how many months earlier the loan closes and how much interest you save. Check first that your lender allows early repayment without a fee.
APR and interest rate
The interest rate is the cost of borrowing the money. The APR (annual percentage rate) also includes certain fees, so it is usually a little higher and is the better number for comparing offers. Enter the rate the lender uses to calculate your payments; if you only have the APR, the result will be a close estimate.
Tips before you borrow
- A longer term lowers the monthly payment but raises the total interest. Compare both numbers, not just the monthly one.
- Check for arrangement or origination fees, which are not part of the monthly payment.
- For a home purchase, use the Mortgage Calculator, which adds property tax, insurance and fees.