A remortgage swaps your current rate for a new one. The headline rate matters, but fees and how long you will stay on the deal decide whether you really save.
How it’s worked out
We calculate standard capital-and-interest monthly payments for your remaining term at the current rate and the new rate:
M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where r is the monthly rate and n is months left.
- Monthly saving = current payment − new payment
- Total saving = (current payments over the term) − (new payments + fees)
- Break-even = fees ÷ monthly saving (in months)
Worked example
£200,000 balance, 25 years left, 5.5% → 4.0%, £999 fees: the monthly payment falls and fees are typically recovered in a small number of months if the rate cut is meaningful. Check early repayment charges on your existing deal before switching.
Frequently asked questions
When does remortgaging make sense?
If the monthly saving covers fees within a period you are happy to stay on the deal — often well before the new fixed term ends — remortgaging can be worthwhile. Factor in early repayment charges on your current deal.
Are fees included?
Enter arrangement, valuation and broker fees as a single total. This calculator adds them to the cost of the new deal when working out total saving and break-even months.
Sources
- Income Tax rates and Personal Allowance (checked 5 October 2026)
- Scottish Income Tax rates (checked 5 October 2026)
- Rates and thresholds for employers 2026 to 2027 (checked 5 October 2026)
- National Insurance: how much you pay (checked 5 October 2026)
- National Insurance rates and categories (checked 5 October 2026)
- 2026 to 2027: Student and Postgraduate Loan deduction tables (checked 5 October 2026)
- Tax on dividends (checked 5 October 2026)
- Corporation Tax rates and allowances (checked 5 October 2026)
- Income Tax — changes to tax rates for property, savings and dividend income (checked 5 October 2026)