What this UK remortgage calculator helps you do
If you are nearing the end of a fixed deal, this remortgage calculator gives you a quick way to compare your current mortgage against a new offer. It estimates your monthly payment change, the effect of fees, and how long it can take to recover remortgaging costs.
In the UK, many borrowers see repayments jump once their introductory period ends and they move to the lender's standard variable rate (SVR). A remortgage can reduce costs, but only if you account for more than just the headline rate. Product fees, legal costs, valuation charges, cashback, and early repayment charges can all change the real outcome.
How to use the calculator
- Outstanding balance: Enter what you still owe.
- Remaining term: Enter years left on your mortgage.
- Current rate vs new rate: Compare your existing deal with the potential remortgage.
- Fees and charges: Include arrangement fee, legal costs, valuation, and any ERC.
- Cashback: Add any lender incentive that offsets costs.
- Add fees to loan: Tick this if you plan to roll fees into borrowing rather than paying them upfront.
The calculator then shows a side-by-side estimate of monthly repayments and total cost impact over your remaining term.
Important UK remortgage costs to include
1) Product or arrangement fee
Some remortgage products have low rates but higher fees. On larger balances these deals can still be great value, but on smaller balances the fee can wipe out the benefit.
2) Early repayment charge (ERC)
If you leave your current deal early, your lender may apply an ERC. This can be a major cost, so always check your mortgage offer document before switching.
3) Legal and valuation fees
Many remortgage packages include free legal work and free valuations, but not all. Where these are payable, include them in your comparison.
4) Cashback and incentives
Cashback can reduce effective remortgage costs and shorten (or eliminate) your break-even period.
Break-even point: why it matters
A lower monthly payment is useful, but remortgaging usually involves one-off costs. The break-even point tells you how many months of savings it takes to recover those costs.
Example: if a new deal saves £120 per month and your net upfront cost is £1,200, your break-even is about 10 months. If you plan to move home in six months, that deal may not be worth taking.
Simple example scenario
Suppose you owe £220,000 over 22 years. Your current rate is 5.69%, and a new rate is 4.42%. With a £999 product fee and £300 legal fees, your monthly payment may drop significantly. But whether it is truly better depends on how long you stay on the deal and whether fees are paid upfront or added to the loan.
Use the calculator with your own numbers and run a few versions:
- Best-case (no ERC, free legals, cashback included)
- Realistic middle case (some fees payable)
- Conservative case (higher fees, possible follow-on rate risk)
Should you shorten term, keep term, or extend?
This page compares deals on the same remaining term to keep things fair. In practice, you can also change term when remortgaging:
- Shorter term: Higher monthly payments but less total interest.
- Same term: Cleaner apples-to-apples comparison.
- Longer term: Lower monthly payments, but usually more interest overall.
Quick remortgage checklist (UK)
- Check your current deal end date and any ERC window.
- Know your estimated property value and loan-to-value (LTV).
- Gather payslips, bank statements, and ID documents.
- Compare total cost, not just the initial rate.
- Review what happens when the initial fixed/tracker period ends.
Final thoughts
A good remortgage can cut monthly payments and reduce long-term interest, especially when rates have fallen or your LTV has improved. The key is full-cost comparison. Use this UK remortgage calculator to estimate monthly impact, fee recovery time, and overall savings before making a decision.
If you want tailored advice, speak with a regulated UK mortgage broker who can review criteria across multiple lenders and match products to your plans.