How to Calculate Remortgage Savings in the UK: Step-by-Step Guide

Updated · Property and mortgages

Introduction

Buying or remortgaging a UK home involves a string of calculations, from stamp duty and deposits to monthly repayments. Doing them before you speak to a broker or agent puts you in a much stronger position.

This guide explains how to calculate remortgage Savings in the UK, step by step. Compare your current mortgage with a new deal and see how fast fees are paid back. You'll see the formula, a fully worked example and practical tips for UK readers.

What this calculation covers

Compare your current mortgage with a new deal and see how fast fees are paid back.

A few percentage points on LTV, rate or tax can change what you pay by thousands of pounds. Running the numbers early helps you set a realistic budget and compare deals properly.

The method and formula

We calculate the monthly payment on your remaining balance at both rates. The break-even point is the fees divided by the monthly saving.

Every figure on our remortgage Calculator follows this method, so you can check the working yourself.

Worked example

Here's a typical example using these figures:

InputValue
Remaining balance£200,000
Current rate6 %
New rate4.5 %
Remaining term (years)20
Fees for new deal£999

Running them through the method gives:

ResultValue
Monthly saving£167.56
Current payment£1,432.86
New payment£1,265.30
Months to recover fees6
Saving over 2 years after fees£3,022.52

The headline figure is monthly saving: £167.56. Change any input and the result will move with it.

How to use the calculator

  1. Enter or choose remaining balance (£).
  2. Enter or choose current rate (%).
  3. Enter or choose new rate (%).
  4. Enter or choose remaining term (years).
  5. Enter or choose fees for new deal (£).
  6. Read your results. The main figure is shown at the top, with a breakdown underneath.
  7. Try different values to compare scenarios side by side.

Tips for UK readers

  • Stamp duty rules differ by nation: SDLT in England and Northern Ireland, LBTT in Scotland and LTT in Wales.
  • Lenders price mortgages in LTV bands, so a slightly bigger deposit can unlock a noticeably lower rate.
  • Always compare the total cost of a mortgage deal including fees, not just the headline rate.
  • Most lenders let you overpay up to 10% of the balance each year without early repayment charges.

Frequently asked questions

What's the quickest way to work out remortgage Savings?

Use our free remortgage Calculator. It applies this method automatically: We calculate the monthly payment on your remaining balance at both rates. The break-even point is the fees divided by the monthly saving.

Do these calculators cover Scotland and Wales?

Yes. We have separate calculators for LBTT in Scotland and Land Transaction Tax in Wales, as well as SDLT for England and Northern Ireland.

Are the mortgage figures a mortgage offer?

No. They are estimates. A lender's decision depends on your credit history, outgoings and their own affordability checks.

How accurate is the monthly repayment?

It uses the standard repayment formula and matches lender illustrations closely for a fixed rate, but actual payments can vary if your rate changes.

Summary

To work out remortgage Savings, follow the method above: We calculate the monthly payment on your remaining balance at both rates. For a quick, accurate answer with your own figures, use the calculator.

Try the remortgage Calculator

Enter your own figures and get an instant answer – free, no sign-up.

Open the remortgage Calculator

Next, read Remortgage Savings: Common Mistakes, Tips and FAQs.

More property and mortgages guides

This guide is general information, not financial, tax, legal or medical advice. Figures use 2025/26 UK rates where relevant. Always check GOV.UK or NHS.uk for official guidance.