Use this free online mortgage overpayment calculator for the UK to estimate how much interest you could save and how much sooner you might repay your mortgage by making extra payments.
Enter your mortgage balance in pounds (£), interest rate, mortgage term, monthly overpayment, and a one-off lump-sum overpayment to compare the estimated costs with and without overpayments.
Calculate Your Mortgage Overpayment Savings
Overpaying your mortgage can reduce the outstanding balance, meaning less interest may accrue over time. Regular monthly overpayments can gradually reduce your balance, while a lump-sum payment can make a larger reduction at once.
Use the calculator to test different amounts and see how your potential interest savings and repayment timeline may change.
To compare your regular repayments, use our Mortgage Calculator UK. You can also explore your expected monthly cost with the Mortgage Payment Calculator UK.
Compare Mortgage Terms and Rates
The potential benefit of overpaying depends on your outstanding balance, interest rate, remaining term, and how much you can comfortably afford to pay. If you are considering a new mortgage deal, use our Mortgage Rate Comparison UK to compare rates, or explore potential savings from switching with the Remortgage Calculator UK.
Check Your Lender’s Overpayment Rules
Before making extra payments, check whether your mortgage allows unlimited overpayments or has an annual allowance. Some UK fixed-rate mortgages limit the amount you can overpay without an early repayment charge. Your lender’s rules determine whether a monthly overpayment or lump sum is suitable for your mortgage.
The calculator provides an estimate rather than a lender quotation. Actual interest savings and the time saved may differ because of your mortgage terms, payment dates, interest calculation method, and lender fees.
Disclaimer: This calculator provides estimates for informational and educational purposes only, not financial, tax, legal, or professional advice. Results are based on the information entered and may differ from actual costs, payments, rates, fees, or eligibility. Verify details with the relevant lender, financial professional, or official source before making financial decisions.
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Disclaimer
MortgageRatesChecker provides educational mortgage calculators, loan tools, and financial guides designed to help you better understand home financing. Our content is researched, fact-checked, and regularly updated in accordance with our Editorial Policy, using trusted information from our Data Sources and transparent methodologies explained in How We Calculate. Learn more about our commitment to accuracy on Why Trust Us. This content is provided for informational purposes only and should not be considered financial, legal, tax, investment, or mortgage advice. Mortgage rates, lending requirements, loan programs, and regulations may change without notice. Before making any borrowing, refinancing, or home-buying decision, consult your Bank or Mortgage Lender, licensed financial advisor, tax professional, or attorney based on your individual circumstances. MortgageRatesChecker is an independent educational resource and is not a lender, mortgage broker, financial advisor, or government agency. Please review our Affiliate Disclosure, Advertiser Disclosure, Disclaimer, and Terms & Conditions for additional information.
