Find Out If Switching Is Worth It After the Fees and Charges
A lower interest rate looks like an easy win, but the saving only counts once the fees and any early repayment charge come off. This calculator sets your current mortgage beside a new deal and shows the monthly saving, the cost of switching and the point at which the switch has paid for itself. If you want the wider picture of how remortgaging works, our guide takes you from the first quote to completion.
Refinance Mortgage Calculator UK
Compare your current mortgage with a new deal and see the monthly saving, the costs and the break-even point.
Get a formal quote
Happy with the figures? Open the form below and your results are added to the message box for you. Add your details and anything else we should know, send it, and an adviser will come back with lender options and a formal quote.
How to Use the Refinance Mortgage Calculator
Start with your home. Enter its value, your outstanding balance, the rate you pay now and the years left on the term. If your deal is about to end, use the standard variable rate you will move to, since that is the payment you are really comparing against.
The new deal comes next: the rate you have been quoted, the term you want and whether it is repayment or interest only. Pick a two-year or five-year fix, and the saving is measured across that period.
The third section holds the costs. Put in the product fee, legal and valuation costs and any early repayment charge, and tick the box if you plan to add the fee to the loan. Money you want to borrow on top goes in its own field, which stops it muddying the comparison.
What the Monthly Saving Tells You
The headline figure sets your current payment against the new payment on the same balance, which isolates what the rate change is worth. Any extra borrowing appears on a separate line, so raising money for a kitchen or a loft neither inflates nor shrinks the saving.
Switching between capital repayment and interest only needs care. The two clear different amounts of the loan, so the comparison stops being like for like, and the calculator flags it when you do.
The Costs of Switching
Most remortgage deals carry a product fee. You can pay it on the day or add it to the loan, and adding it spares you the bill but means paying interest on it for the full term, which usually costs more in the long run. Plenty of deals include free legal work and a free valuation, so find out what your lender covers before you fill in those fields.
Early repayment charges are the cost people overlook. Leave a fixed or discounted deal early and your current lender can charge a percentage of the balance, which can wipe out a year or more of savings. Our page on early repayment charges explains how they work and how to find yours.
Break-Even: When Switching Starts to Pay
Break-even tells you when the switch has paid for itself. Divide the upfront costs by the monthly saving and the answer is the time you need to stay on the new deal before you come out ahead. Five months is an easy decision, while eighteen only suits someone who expects to keep the deal that long.
The fixed period shapes the result. A two-year fix gives you two years to bank the saving before you have to switch again, while a five-year fix gives you longer but commits you for longer. The calculator shows the net saving over whichever period you choose, after costs.
Worked Example: Moving From 6.5 Percent to 4.5 Percent
Take a home worth £350,000 with a £200,000 mortgage and 20 years left on repayment. At 6.5 percent the payment is £1,491 a month, and a new deal at 4.5 percent over the same term brings it down to £1,265.
The saving comes to £226 a month. With a £999 product fee paid upfront and no other charges, the switch breaks even in about five months. Over a two-year fix the net saving is about £4,400, and over five years it is about £12,550. The loan to value is 57 percent before and after, so there is no change in the rate band.
More Examples to Try
Change a few boxes in the example above and the answer shifts in useful ways. If you add the £999 fee to the loan instead of paying it, there are no upfront costs and the saving is £220 a month, but you pay interest on the fee until the mortgage ends.
Suppose you also want to raise £20,000 for home improvements. The new loan is £220,000, the loan to value rises to 63 percent and the extra borrowing adds £127 a month, bringing the total payment to £1,392. The £226 saving on your existing balance does not change.
The early repayment charge has the biggest effect. With a £3,000 charge on top of the £999 fee the upfront cost is £3,999, break-even moves to about eighteen months and the two-year net saving falls to about £1,420. If your deal ends in six months, waiting would forgo about £1,355 of saving but avoid the £3,000 charge, so on these figures waiting is the better choice.
What the Calculator Cannot Tell You
The figures are only as good as the rate you type in. Rates change daily, lenders price in loan to value bands, and the deal you are offered depends on your credit history, income and the property. A rate shown on a comparison site may not be the rate you qualify for.
You also have a choice between moving to a new lender and switching to another deal with your current one. Our comparison of remortgage and product transfer sets out when each makes sense. A specialist mortgage adviser can compare the whole market, check the costs against your savings and tell you whether to switch now or wait.
Frequently Asked Questions
Is it worth remortgaging?
Yes, when the monthly saving, added up over the fixed period, comes to more than the costs of switching.
The calculator shows the break-even point and the net saving after costs, so you can see where your case falls.
How much does it cost to remortgage?
It depends on the deal.
You may pay a product fee, legal and valuation costs and, if you leave early, an early repayment charge, although many deals include free legal work and a valuation. Enter the figures from your own quote to see the real cost.
What is the break-even point on a remortgage?
It measures the time needed to recover the upfront costs.
If a switch costs £1,000 and saves £200 a month, it breaks even after five months, and every month after that adds to your net gain.
Can I remortgage to borrow more?
Often, yes.
You can raise extra money against your home, subject to the lender’s affordability checks and a maximum loan to value. The calculator shows the extra payment and how the borrowing changes your loan to value.
When should I start looking for a new deal?
Many lenders let you secure a new rate several months before your current deal ends, and acting early protects you from moving onto the standard variable rate.
Our page on what happens if you do not remortgage after a fixed term explains the risk.
Do early repayment charges apply when my deal ends?
Usually not once the fixed or discounted period has finished, which is why timing a switch for the end of the deal can avoid them.
During the deal they are commonly a percentage of the balance you repay, so check your paperwork.
Will remortgaging affect my credit score?
A full remortgage application includes a hard search, which can cause a small, short-lived dip.
Using the calculator does not touch your credit file, and our guide on what a mortgage application does to your credit report explains how searches work.
Final Thoughts
Run the numbers above, then talk them through with an adviser before you commit to a new deal. We can compare lenders, check the costs and tell you when the timing suits you.
UK Mortgage Broker is a whole-of-market broker helping clients throughout the UK and globally to secure funding on UK property. We are directly authorised and regulated by the Financial Conduct Authority. Your home may be repossessed if you do not keep up repayments on your mortgage.
Call: +44 1628 969 500
Email: info@uk-mortgagebroker.co.uk
Related Pages
- UK Mortgage Rates – current rates across the whole market to benchmark your remortgage.
- Fixed vs Tracker Mortgages in 2026 – how fixed and tracker rates compare, to help you choose between deal types.
- Best Time to Refinance a Mortgage – when to start looking for a new deal and why timing matters.
- Simple Mortgage Calculator – a quick tool for monthly repayment estimates.