Loan calculator
Loan payments, with the interest shown.
Work out the monthly payment on a fixed installment loan, see the total interest, and test what an extra payment each month would do.
Calculator
Assumptions. This is a fixed-rate, fully amortizing installment loan with monthly payments. Fees, origination charges and variable rates aren’t included. At a 0% rate, the required payment is the amount divided by the number of months.
How the payment is calculated
The same amortization math used for mortgages applies to personal loans, auto loans and similar installment debt. Interest is charged on the remaining balance each month; the rest of your payment reduces principal. An optional extra payment goes straight to principal and can shorten the term and cut total interest.
Formula
Worked example
A $15,000 loan at 7.9% APR for 5 years has a monthly payment of $303.43. Over 60 months you repay about $18,206, of which roughly $3,206 is interest. Adding an extra $50 a month pays the loan off sooner and reduces the interest.
Extra payments and a set payment
An extra monthly amount or a one-time lump sum goes straight to principal, so less interest builds up each month after it. If you choose Pay a set amount, enter the monthly payment you plan to make, and the calculator works out how many months the loan takes and what you save against the standard schedule. The payment has to be more than the first month’s interest, or the balance would never fall. The final payment is only what’s left, so you never overpay.
Example: the same $15,000 loan at 7.9% with a set payment of $400 a month is paid off in 44 months instead of 60, and the interest falls from about $3,206 to about $2,284.
When to use it
- Comparing loan offers with different rates or terms.
- Checking whether an extra monthly payment is worth it.
- Estimates only: lenders may use different day-count rules or fees. For mortgages with taxes and insurance, use the mortgage calculator.