Periodic payment, total interest and total repayment.
What it's for
Work out the regular payment on a loan — a car, a house, a personal loan — and how much it costs in interest over the whole term.
Before you start
Have the amount you will borrow, the yearly interest rate and how many years you will pay. Ask the lender whether interest is charged on what you still owe or as add-on interest; this page does the first.
Enter the loan amount
Type how much you are borrowing in Amount borrowed. Commas are fine here.
Enter the rate and the term
Type the yearly rate in Annual rate (%) — just the number, 6 for 6% — and the length of the loan in Term (years). Part of a year is fine, such as 2.5.
Choose how often you pay
In Paid, choose Monthly, Semi-monthly (twice a month), Quarterly or Annually to match your payment schedule.
Press Calculate
Press Calculate. The answer already updates as you type; the button brings it into view.
Open the schedule, if you want each payment
Beside Schedule, press Show all to list every payment, split into interest and principal, with the balance left after it. Press Hide to close the list.
Reading the result
If it goes wrong
An amortised loan is repaid in equal instalments, each covering the interest that has accrued plus a slice of the principal. The payment never changes; the split does. Early on, most of it is interest, because interest is charged on what you still owe. By the end, almost all of it is principal.
The rate you enter is the nominal annual rate. It is divided by the number of payments in a year to get the rate per period — not by the total number of payments, which is a common and expensive mistake.
No, and the difference is large. This calculator amortises: interest is charged on the balance still outstanding, which falls with every payment. Add-on interest charges the full rate on the original amount for the whole term, regardless of what you have already repaid — so the same headline rate costs you considerably more. If your lender quotes a monthly add-on rate, the true annual cost is far higher than the number they give you.
Because interest is charged on what you still owe, and early on you still owe almost everything. The payment stays the same each period, but the split shifts steadily from interest toward principal. Open the schedule to see it.
Yes, slightly. Paying twice a month rather than monthly reduces the balance sooner, so less interest accrues. The effect is real but modest — the interest rate matters far more than the frequency.
A zero-interest loan is simply the amount borrowed split evenly — the formula above divides by zero at that point, so it is handled separately.
Important
This is an estimate for an amortised loan. Lenders add fees, insurance and other charges this does not model, and many quote add-on interest rather than amortised interest. Nothing you type here is sent to our servers — the calculation runs entirely in your browser.
