Lump-sum mortgage overpayment calculator UK
Model a one-off capital payment while keeping the regular mortgage payment unchanged. Check the formula, worked example and limits before using your own figures.
Enter your figures
Interest saved in the model
Inputs changed. Select Calculate result to update your estimate.
Use your actual figures. Any prefilled price, fee, rate or return is an editable illustration, not a current product quote. Assumes the overpayment is allowed without fees and shortens the term. No early repayment charges, future rate changes or savings-return comparison.
How the lump-sum mortgage overpayment calculator uk works
Compare payoff schedules before and after subtracting a one-off payment from capital.
Data basis: mathematical formula using your inputs. Example prices and rates are illustrative, not current market quotes.
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Worked example: lump-sum mortgage overpayment
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
- Lump-sum payment (£)
- 10,000
Interest saved in the model: £19,300.45
Compare payoff schedules before and after subtracting a one-off payment from capital.
Lump-sum mortgage overpayment: questions answered
What does the lump-sum mortgage overpayment calculation include?
Compare payoff schedules before and after subtracting a one-off payment from capital. Use your actual figures. Any prefilled price, fee, rate or return is an editable illustration, not a current product quote. Assumes the overpayment is allowed without fees and shortens the term. No early repayment charges, future rate changes or savings-return comparison.
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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