Mortgage Repayment Calculator
Work out the monthly repayment on a mortgage from the loan amount, rate and term, see the total interest, and test what an overpayment each month saves.
Guide
How the repayment is worked out
Interest is charged each month at the yearly rate divided by 12. The level repayment that clears the loan over n payments is loan × r ÷ (1 − (1 + r)−n), where r is the rate for one period.
For example, £200,000.00 at 4.5% over 25 years is £1,111.66 a month. That is 300 payments, £333,499.49 in all, so £133,499.49 of it is interest. The rate, term and loan amount here are placeholders, not a quote.
What is not included
This is the repayment of the loan itself, principal and interest. Fees, insurance, any package or account charges and changes to the rate are not included, and it assumes one rate for the whole term. If your rate changes, enter the new rate, the balance still owing and the years left.
Extra repayments
Anything you pay above the repayment goes towards the amount you owe, so less interest is charged from then on. An extra £200 a month on the example above pays the loan off in 18 years 11 months instead of 25 years, and saves £36,280.39 of interest. Put an amount in the extra box to try your own.
Some lenders limit or charge for extra repayments on fixed-rate loans, so ask yours.
Offset accounts and one-off payments
An offset account is a transaction or savings account linked to the loan. Interest is charged on the loan less the balance in the account, so money sitting there saves interest as if it had been paid off, and you can still take it out. On the example, keeping £20,000.00 in the offset account the whole time pays the loan off in 22 years 4 months instead of 25 years and saves £35,968.47 of interest. The calculator assumes the balance stays the same for the whole loan and that the repayment is unchanged, so a balance that rises or falls will change the result. Not every loan has an offset, and some charge a fee or a higher rate for one.
A one-off payment now reduces the amount you owe straight away. On the example, paying £5,000.00 on day one pays the loan off in 23 years 11 months and saves £10,011.14 of interest. You can use the one-off box, the extra box and the offset box together.
Term and rate
A longer term lowers the repayment but costs more interest, which the comparison table shows. A higher rate costs more too: on the example, 5.5% instead of 4.5% makes the repayment £1,228.17 a month.
Common questions
Does this include fees and insurance?
No. It is the repayment of principal and interest only. Fees, insurance and rate changes are not included.
How much does an extra payment save?
On £200,000.00 at 4.5% over 25 years, an extra £200 a month saves £36,280.39 of interest and shortens the loan by 6 years 1 month. Your own numbers will differ, so enter them.
Why is so much of the early payment interest?
Interest is charged on the whole balance. In the first month of the example, £200,000.00 at 4.5% a year is £750.00 of interest, so only £361.66 of the £1,111.66 reduces the loan. The share that reduces the loan grows each month.
Is the interest rate fixed?
This assumes the same rate for the whole term. If your rate is variable or a fixed period ends, run it again with the new rate, the balance owing and the years left.
What next?
- Clearing a card as well? See how long a monthly payment takes. Credit Card Repayment Calculator
- Saving a deposit? See how savings grow. Savings Interest Calculator (Compound Interest)
- Planning home improvements? Estimate the materials with Handyfig