UK Mortgage Repayment Calculator
Estimate monthly payments and total interest using a single mortgage rate and term.
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Switching deal estimate
Remortgage Comparison Calculator
Compare your current mortgage rate with a new deal and estimate the monthly saving, net saving after fees and break-even point.
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- ✓Monthly saving, gross and net saving after fee
- ✓Fee break-even point calculation
- ✓Fixed, tracker or new lender deal comparison
Calculate your remortgage saving
Enter your mortgage balance, current rate, new rate and new deal fee. The calculator compares the monthly payments and shows whether the fee is recovered during the chosen period.
How to use this calculator
- Enter your current mortgage balance and remaining term.
- Add your current rate and the new deal rate.
- Enter the new deal fee, if there is one.
- Choose the period you want to compare, such as 2 or 5 years.
Remortgage comparison formula
current_payment =
repayment_formula(balance, current_rate, term)
new_payment =
repayment_formula(balance, new_rate, term)
monthly_saving =
current_payment - new_payment
gross_saving =
monthly_saving × comparison_months
net_saving =
gross_saving - new_deal_fee
break_even_months =
new_deal_fee / monthly_saving
A positive net saving means the new deal saves more than the fee during the comparison period. A negative net saving means the fee or higher payment outweighs the saving.
Net saving after fee
£4,309.14
Estimated saving over the comparison period after the new deal fee.
Current monthly payment
£1,610.75
Estimated repayment at your current mortgage rate.
New monthly payment
£1,389.58
Estimated repayment using the new deal rate.
Monthly saving
£221.17
Difference between the current and new monthly payment.
Gross saving before fee
£5,308.14
Monthly saving multiplied by the comparison period.
Fee break-even point
4.5 months
Estimated time needed for the monthly saving to recover the new deal fee.
Lower monthly payment
Break-even inside period
This estimate does not include early repayment charges, exit fees, legal fees, valuation fees or broker fees.
Ready to act on your result?
If the new deal saves money after fees, compare mortgage deals and check the full cost before switching.
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What your remortgage result means
The monthly saving shows the difference between your current payment and the payment estimated using the new rate. If the figure is positive, the new deal is cheaper each month before fees.
The gross saving shows how much those monthly savings add up to across the comparison period. The net saving then subtracts the new deal fee (sometimes called an arrangement fee), which gives a more useful view of whether the switch is worthwhile.
The break-even point shows how long it takes for the monthly saving to recover the fee. A short break-even point is usually more attractive than one close to the end of the deal period.
Do not compare rate alone: a lower rate can still be worse if the fee is high, the saving is small, or you leave the deal before the break-even point.
How remortgage comparison works
Remortgaging means moving your mortgage onto a new deal, either with your current lender or a different lender. People usually compare remortgage options when a fixed or tracker deal is ending, or when their current rate has risen to the standard variable rate.
The simplest comparison starts with the monthly payment. If the new rate is lower, the monthly repayment may fall. However, that saving is only useful if it is large enough to justify any fees.
Product fees can change the true cost of a deal. A low-rate fixed-rate mortgage with a high fee may be worse than a slightly higher-rate mortgage with no fee, especially on smaller mortgage balances or shorter deal periods.
The break-even point helps you judge the fee. For example, if the fee takes 18 months to recover and the deal only lasts 24 months, the benefit may be limited. If the break-even point is four months, the fee may be easier to justify.
This calculator keeps the comparison simple by using the same balance and remaining term for both rates. It does not include early repayment charges, exit fees, legal costs, valuation costs or changes to the mortgage term.
What affects your remortgage saving
- Mortgage balance: Larger balances usually benefit more from a lower rate because the interest saving applies to more debt.
- Current rate: The higher your current rate, the more room there may be for savings.
- New deal rate: A lower new rate can reduce the monthly payment, but it must be judged alongside fees.
- New deal fee: Product or arrangement fees can reduce or remove the saving from a lower rate.
- Comparison period: The longer you keep the new deal, the more time there is for monthly savings to build.
- Early repayment charges: Leaving your current deal early can create a cost this calculator does not include.
- Mortgage term: Changing the term can change monthly payments and total interest, so compare like-for-like where possible.
Remortgage comparison calculator FAQs
How do I know if remortgaging is worth it?
Compare the monthly saving with the total fees and charges. A new deal is more attractive when the net saving is positive and the break-even point is comfortably inside the deal period.
What is a remortgage break-even point?
The break-even point is the number of months needed for the monthly saving to recover the new deal fee. If the break-even point is longer than the deal period, the fee may not be worthwhile.
Does this calculator include early repayment charges?
No. It only includes the new deal fee entered in the calculator. Add any early repayment charge, exit fee, legal fee, valuation fee or broker fee before making a final decision.
Can a remortgage cost more even if the rate is lower?
Yes. If the new deal fee is high or the monthly saving is small, the total cost over the comparison period can be higher even with a lower interest rate.
Should I choose the lowest remortgage rate?
Not automatically. You should compare the rate, product fee, flexibility, early repayment rules, loan-to-value, lender criteria and how long you expect to keep the deal. A tracker mortgage may offer flexibility but carries rate-rise risk.
Should I remortgage or overpay?
It depends on the rate saving, fees, early repayment charges and your cash position. A lower remortgage rate may save more than overpaying, but overpaying can still be useful if fees or lender criteria make switching unattractive.
Key terms used in this calculator
These terms explain the mortgage concepts behind the comparison.