Remortgage Calculator
Compare a current repayment mortgage with a proposed rate and term. The result assumes constant rates and does not model early repayment charges unless entered as fees.
Quick answer
The calculator estimates payment change, fee-adjusted savings and how many months of savings may be needed to recover fees.
Calculator
How to use this calculator
- Enter the figures that match your current scenario.
- Check the effective date, assumptions and any jurisdiction or plan selection.
- Review the breakdown, test a second scenario and verify the result before acting.
Explanation
What it is
The calculator estimates payment change, fee-adjusted savings and how many months of savings may be needed to recover fees.
How it works
Both payments use the amortisation formula. Extending the term can lower the payment while increasing lifetime interest, so compare total cost as well as break-even.
When to use it
Use this tool to explore a planning scenario before checking current official rules, product documents or professional guidance.
Limitations
- The result is an estimate based only on the inputs shown.
- Rates, thresholds and product terms can change after the effective date.
- The calculator does not replace an official assessment, provider quote or personalised advice.
Key terms
- Estimate
- A planning result produced from the stated inputs and assumptions, not a guaranteed outcome.
- Effective date
- The date or tax year for which a changing rule, threshold or rate has been checked.
- Authoritative source
- An official or regulator-backed source used to support a rule, rate or calculation method.
Formula
How we calculate this
Both payments use the amortisation formula. Extending the term can lower the payment while increasing lifetime interest, so compare total cost as well as break-even.
Statutory or methodological reference:MoneyHelper guidance — Remortgaging To Cut Costs.
Formula trace: Standard amortisation and affordability model with capital, interest, term, fees, LTV and overpayment scenarios; disclose assumptions and test 0%, boundary, negative and balloon cases.
Worked example
Enter realistic figures into the remortgage calculator and compare the result with the breakdown. Change one assumption at a time so you can see which factor has the greatest effect. Check the governing rule at MoneyHelper guidance — Remortgaging To Cut Costs.
FAQ
What does the remortgage calculator calculate?
The calculator estimates payment change, fee-adjusted savings and how many months of savings may be needed to recover fees.
Which assumptions have the biggest effect?
The most important assumptions are the amounts, time period, applicable rate or threshold, and any jurisdiction or plan choice shown in the form.
How accurate is this estimate?
It is designed for planning and testing scenarios. Accuracy depends on the inputs and whether your circumstances fit the simplified method described on the page.
Can I use the result as a final decision?
No. Verify changing rules and product terms, and seek suitable professional or official guidance when the decision is material or complex.
When should I recalculate?
Recalculate after a change in income, balance, rate, term, household circumstances, tax year or official policy.
Common mistakes
- Using a headline rate without checking whether it applies to the full amount.
- Mixing monthly and annual figures.
- Treating an educational estimate as an official assessment or guaranteed quote.
Tips
- Test a cautious scenario as well as an optimistic one.
- Keep a note of the assumptions and effective date.
- Compare the result with official guidance or provider documents before acting.
Related calculators
Related guides
Sources and editorial review
- MoneyHelper guidance — Remortgaging To Cut Costs
- Financial Conduct Authority guidance — Mortgages
- MoneyHelper guidance — How Much Can You Afford To Borrow
Author and review
Author: FinanceHub UK Editorial Team — Editorial. Editorial policy.
Reviewed by role: Qualified mortgage adviser and FCA compliance reviewer. Named qualified reviewer sign-off is pending before production.
Review record date: 2026-07-10. Next review due: 2027-03-01.