Mortgage Calculator UK 2026
Calculate your monthly mortgage repayments and see exactly how overpayments reduce your term and save interest. A free UK home loan repayment and mortgage payoff calculator.
See how overpayments cut years and interest.
Repayment per month
£1,390
Buying a property? Don't forget upfront costs
Your repayments are only part of the picture. Estimate SDLT too:
Frequently Asked Questions
How are mortgage repayments calculated in the UK?
Repayments use the standard amortisation formula: P × r ÷ (1 − (1 + r)^−n), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. Early repayments are mostly interest; later ones are mostly capital.
Do overpayments save money on a UK mortgage?
Yes — significantly. Overpayments reduce your outstanding balance, so you pay interest on a smaller amount for the rest of the term. On a £300,000 mortgage at 4.5% over 25 years, an extra £200/month can save over £35,000 in interest and cut 6 years off the term.
Should I pay monthly or weekly in the UK?
Most UK mortgages are paid monthly. Weekly or fortnightly payments are less common with UK lenders than in Australia or Canada, but some lenders allow them. Check your mortgage terms before changing your payment frequency.
What interest rate should I use for a UK mortgage calculator?
Use your current mortgage rate. As of 2025, typical UK 2-year fixed rates are around 4–5% and 5-year fixed rates are around 4–4.5%. For stress-testing, try 1–2% higher to see if repayments are affordable if rates rise.
Does this calculator include SDLT, fees or offset mortgages?
No — it models capital and interest repayments only. Stamp Duty Land Tax, solicitor fees, survey costs, arrangement fees and offset mortgage effects are not included. Use the Stamp Duty Calculator for upfront costs.