Mortgage repayment calculator
See exactly what your monthly payment is and where it goes. Most people know what leaves the account each month. Far fewer know how much of it this year is buying the house rather than paying the bank.
Updated for the 2026/27 tax year · reviewed
Your mortgage
= 20.0% of price
Your monthly payment
£1,013
on a £200,000 loan over 30 years
Loan amount
£200,000
Monthly payment
£1,013
Total repaid
£364,813
Total interest
£164,813
Where your payments go
Cumulative principal repaid vs interest paid, over the mortgage term.
Your payment is settled. Your plan isn't.
See what this mortgage leaves you each month once pensions, savings and everyday spending are in the same picture - and what the balance looks like in ten years.
Create your free accountHow this calculator works
Your loan amount is the property price minus your deposit. We run that loan through the standard UK repayment (amortisation) formula at your rate and term, which produces one fixed monthly payment for the whole mortgage - the same figure every month, even though the split between interest and capital shifts underneath it.
Early payments are mostly interest, because interest is charged on the outstanding balance and that balance is largest at the start. As the balance falls, a growing share of the same payment goes towards capital instead - the chart above shows that shift as cumulative totals over the term.
This assumes a fixed rate and monthly compounding for the entire term, with no overpayments, payment holidays or rate changes along the way. Your real lender's offer, fees and any rate changes will shift the exact numbers - treat this as a close estimate for planning, not a mortgage quote.
Questions people ask
How is my monthly mortgage payment worked out?
A repayment mortgage uses a standard amortisation formula based on the loan amount, interest rate and term, so every monthly payment is identical while the split between interest and capital shifts over time. This calculator uses that same formula on your numbers.
Why does so little go towards the loan at first?
Interest is charged on the outstanding balance, which is largest at the start, so early payments are mostly interest. As the balance falls each month, a growing share of the same payment goes towards capital - this accelerates sharply in the final years.
Repayment or interest-only - what's the difference?
Repayment mortgages clear the balance to zero by the end of the term; interest-only mortgages leave the full loan outstanding unless you have a separate repayment vehicle. Use our interest-only vs repayment calculator to compare the total cost of each.
What happens to my payment if rates rise?
On a fixed-rate deal, nothing changes until the deal ends and you remortgage onto the prevailing rate. On a tracker or standard variable rate, your payment moves with the rate immediately - try a higher rate here to see the effect.
Last reviewed against 2026/27 UK rules. Projections are estimates for education, not financial advice. Understanding your projections.
A calculator answers one question at a time.
The planner keeps all of them next to each other, so an overpayment you model today still shows up in the pension picture in twenty years.
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- Your figures carry over