🏦 Mortgage Overpayment Calculator

See how overpaying cuts your mortgage term and total interest. Add a monthly overpayment, a lump sum, or both, and compare against paying the normal schedule. Full amortisation worked out on your device.

Your mortgage

Balance (£):

Interest rate (%):

Remaining term (years):

Monthly overpayment (£):

One-off lump sum (£):

Fixed-rate catch: many deals allow up to 10% of the balance per year without an early-repayment charge (ERC), typically 1–5% of the overpaid amount above that. Keep at least a 6-month payment buffer if your rate isn't fixed.