Mortgage overpayment calculator UK
Estimate mortgage interest saved and months cut from the term with extra monthly repayments. Compare a fixed-rate repayment mortgage with and without overpayments.
Enter your figures
Estimated interest saved
Inputs changed. Select Calculate result to update your estimate.
Assumes monthly interest, unchanged rate and regular payment, and overpayments used to shorten the term. No fees, overpayment limits or early repayment charges. Final payment is capped at the remaining balance plus interest.
How the mortgage overpayment calculator uk works
Simulate each month with and without the extra payment; compare total interest and months to repayment.
Data basis: mathematical formula using your inputs. Example prices and rates are illustrative, not current market quotes.
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Worked example: mortgage overpayments
This illustration uses the calculator’s example inputs. It is not a quote or a recommended financial decision.
- Outstanding mortgage (£)
- 200,000
- Nominal annual interest (%)
- 4.5
- Years
- 25
- Extra monthly payment (£)
- 100
Estimated interest saved: £21,141.79
Simulate each month with and without the extra payment; compare total interest and months to repayment.
Mortgage overpayments: questions answered
Does this calculator include early repayment charges?
No. It assumes the extra payments are permitted without charges and shorten the term. Check your lender’s overpayment allowance, fees and repayment rules before using the estimate to plan a payment.
Using your result
Example inputs are a starting point. Replace them with your figures and select Calculate result. Results are rounded for display; calculations use unrounded values.
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