Loan / Mortgage Calculator
Monthly payment, total interest, and payoff date for any fixed-rate loan — add an extra monthly payment to see how much time and interest it saves.
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| Year | Principal paid | Interest paid | Remaining balance |
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How to calculate loan or mortgage payments
- Enter the amount you’re borrowing, the annual interest rate and the term in years.
- Optionally add an extra monthly payment.
- Read the monthly payment, total interest and payoff date, and how much time and interest the extra payment saves.
How it's calculated
Uses the standard fixed-rate amortisation formula: payment = P × r(1+r)^n ÷ ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments. Each payment splits between interest (on the remaining balance) and principal; an extra monthly payment goes entirely toward principal, shortening the loan. As with a real loan, the payment and each month's interest are rounded to the penny, and the final payment is adjusted to clear the balance exactly, so the schedule's columns add up to the totals shown.
This is for estimation only — actual loans may include insurance, arrangement fees or other charges not modelled here. Nothing entered is sent to a server.
Questions about loans and mortgages
How much is a £200,000 mortgage per month?
At 5% over 25 years, about £1,169 a month on a repayment mortgage. Enter your own rate and term to see yours.
How much do overpayments save?
Every extra pound goes straight off the balance, so it saves interest for the rest of the loan. Add an extra payment to see the time and interest saved; check your lender’s overpayment limits.
How is the monthly payment worked out?
With the standard amortisation formula. Early payments are mostly interest; as the balance falls, more of each payment goes off the loan.
Does it include fees or insurance?
No. It covers the loan and interest only, so arrangement fees, insurance and other charges are extra.