How much can I save by overpaying my mortgage?
Overpayments cut interest and may shorten the term. The comparison tiles show interest saved and months gained.
Mortgage Overpayment Calculator
See how regular or lump-sum overpayments on a repayment mortgage could reduce interest and shorten your term.
Your mortgage
Interest saved
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Time saved
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Total cost saved
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Comparison
| Standard | With overpayment | Saving |
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Balance remaining
Total interest paid
Interest paid per year
Annual interest declines as your balance falls. Overpayments reduce interest each year and shorten the schedule.
How this calculator works
It models a repayment mortgage with optional monthly or one-off overpayments. Interest is calculated on the reducing balance; charts compare total interest and term with and without overpayments.
Who this is for
UK homeowners weighing whether extra payments are worthwhile. Budget purchase costs with the stamp duty calculator before committing to a property price.
Assumptions
Fixed interest rate, no lender fees, ERCs or annual overpayment caps. Your lender’s payment may differ slightly from the calculated standard payment.
Frequently asked questions
Should I overpay my mortgage or save instead?
Overpaying earns your mortgage rate but reduces flexibility. Keep an emergency fund before large overpayments.
Does this include lender overpayment limits?
No. Check your mortgage terms — fixed-rate deals often cap annual overpayments without fees.
How does stamp duty relate to my mortgage?
Stamp duty is paid upfront on purchase. Use the stamp duty calculator when planning deposit and buying costs.
Important: Figures are indicative estimates based on the information you enter. Lender rules, fees, and rate changes are not modelled. This tool is for planning and illustration only and does not constitute regulated financial, tax or investment advice.