Monthly repayment, total interest and a full amortization schedule — for mortgages, car loans and personal loans
| Year | Principal paid | Interest paid | Remaining balance |
|---|
Monthly payment = P × r ÷ (1 − (1 + r)−n), where P is the amount borrowed, r the monthly interest rate (annual ÷ 12) and n the number of monthly payments. This is the standard amortized-loan formula banks use.
Each payment covers that month's interest first; only the remainder reduces your balance. Early in a long loan most of the payment is interest — the schedule below shows the balance shrinking faster every year.
A longer term lowers the monthly payment but raises total interest dramatically. Compare 30 vs 15 years on the same loan here — the monthly difference is smaller than most people expect, the interest difference is huge.
Mortgages, car loans, personal loans and student loans all follow the same math. Enter the amount, rate and term from your loan offer to see its real total cost before signing.
Results exclude fees, insurance, taxes and rate changes on variable loans — lenders' "comparison rate" includes some of these. Treat the output as a close estimate, not a quote.
Everything is calculated in your browser. Your loan details are never sent to a server — nothing to store, nothing to leak, no sign-up.