Mortgage Payment Calculator
This mortgage payment calculator works out the monthly payment on a fixed-rate loan. It also shows the total interest you would pay over the loan and the total amount paid back in all. You enter the loan amount, the interest rate (APR) and the term in months, and the results appear straight away.
A year-by-year schedule shows how each payment is split between interest and the amount you owe. Early payments contain more interest, and the balance falls gradually over the term. Use the figures to compare options before you speak to a lender or bank.
Year-by-year schedule
How to use the mortgage payment calculator
- Enter the loan amount in pounds (£) in the first box. This is the sum you plan to borrow.
- Enter the interest rate (APR) as a percentage in the second box.
- Enter the term in months in the third box. For example, a term of three years is 36 months.
- Read the monthly payment, which is the amount you would pay each month.
- Check the total interest and the total paid to see the full cost of borrowing.
- Look through the year-by-year schedule to see how the balance reduces over time.
The formula
- Monthly payment = P × r ÷ (1 − (1 + r) ^ −n), where P is the amount borrowed, r the annual rate ÷ 12 ÷ 100 and n the number of months
- Total paid = the monthly payments added up; total interest = total paid − loan amount
- Each month: interest = balance × annual rate ÷ 12; the rest of the payment reduces the balance
Worked example
The figures below are made up to show the maths. They are not current prices, rates or product figures.
| Loan amount | £10,000.00 |
|---|---|
| Interest rate (APR) | 8% |
| Term | 36 months |
- Monthly payment £313.36
- Total interest £1,281.09
- Total paid £11,281.09
Tips for an accurate answer
- Make sure the rate you enter is the APR, as this figure includes the cost of the loan over its term.
- Enter the term in months, not years, to avoid a result that is far off what you expect.
- Try a few different loan amounts and terms to see how each change affects the monthly payment.
- Remember that the calculator works on a fixed rate for the whole term, so it does not allow for rate changes.
- Check your final figures with the lender or bank before making any decisions, as they hold the exact terms of your loan.
Questions people ask
Can I use this mortgage calculator for a UK mortgage?
Yes, the calculator works in pounds (£) and uses metric units, so it suits UK loans. Enter the loan amount, the APR and the term in months to see the results. Check the final figures with your lender, as they hold the exact terms.
Does this calculator work for an interest only mortgage?
This calculator is designed for a fixed-rate repayment loan, where each payment reduces the balance. It does not separately show an interest only arrangement. Speak to your lender about how interest only terms would work for you.
Where can I find an older mortgage calculator?
This page provides a current mortgage payment calculator that you can use right away. Enter your loan amount, interest rate and term in months to get your results. For the exact terms of any loan, check with your lender.
What does this mortgage payment calculator work out?
It works out the monthly payment, the total interest and the total paid on a fixed-rate loan. It also shows a year-by-year schedule of how the balance falls. All results are based on the figures you enter.
What do I need to enter?
Enter the loan amount, the interest rate (APR) as a percentage and the term in months. The calculator uses these three figures to produce every result on the page.
How is the total interest worked out?
The calculator adds up all the monthly payments and then subtracts the loan amount. The difference is the total interest. In the worked example, a £10,000.00 loan at 8% over 36 months gives total interest of £1,281.09.
Why does the balance fall slowly at first?
Each month, interest is charged on the balance that is still owed, so more of each early payment goes towards interest. As the balance reduces, a larger share of each payment goes towards the amount you owe.
Is this calculator financial advice?
No, it is a maths tool only. Check the figures with your lender or bank, as they can confirm the exact terms and any fees that apply to your loan.
Sources
This calculator uses the standard loan and interest formulas above and the numbers you type. It needs no outside figures.
An estimate from the numbers you enter, worked out with the formula shown. It is maths, not financial advice: your lender or bank has the final figures. Page checked 23 Oct 2026. Read the disclaimer