UtilibyWritten by the Utiliby editorial team · Last updated October 15, 2026 · Rules and formulas reviewed October 2026
What this free online UK remortgage calculator does
A good remortgage can save you hundreds of pounds a year. A badly timed one can cost you thousands in early repayment charges and fees. This free online remortgage calculator for the UK puts both sides on one page, in pounds, so you can see whether a new deal is worth it, how long it takes to repay the costs and whether it is better to wait until your current deal ends.
Enter your current balance, rate and deal end date, the early repayment charge, and the rate and fees on the deal you are considering. The calculator shows your new payment, the monthly saving, the break-even month, the lifetime interest saved and a month-by-month savings chart. Everything runs in your browser, so your figures stay private.
How to use the remortgage calculator
- Enter your current mortgage. Use the balance, the rate and the years left. Your latest statement shows these.
- Add the deal end and the charge. Enter how many months are left on your deal and the early repayment charge as a percentage. If your deal has ended, enter 0 months and no charge applies.
- Enter the new deal. Add the new rate, the term and every fee, and any cashback.
- Choose how to pay the costs. Pay them up front or add them to the mortgage.
- Read the results. Look at the break-even, then open the Wait tab to compare switching now with waiting for the end of your deal.
Early repayment charges and timing
An early repayment charge is the main reason people lose money when they remortgage. It is usually a percentage of the balance, and the percentage often steps down each year of the deal. On a 180,000 balance, a 2% charge is 3,600, which is a lot to recover through a lower rate.
The timing question has a simple shape. If your deal ends in a few months, waiting costs you the extra interest on those months at your old rate. If it ends in two years, the charge may be worth paying, but only if the monthly saving is large. The Wait tab compares the two and shows which is better over the time you will keep the new deal. Many lenders let you secure a new deal some months before your current one ends, so you can often avoid both the charge and the standard variable rate. Check with your lender and a broker how far ahead you can book.
Worked example
A homeowner owes 180,000 at 5.5% with 20 years left, and the deal ends in six months with a 2% early repayment charge of 3,600. A new 4.4% deal over 20 years has a 999 product fee. The monthly payment falls from about 1,238 to about 1,129, a saving of roughly 109. Switching now costs about 4,600 in charge and fee, so the break-even is about 43 months. Waiting six months avoids the charge and forgoes only about 650 of savings, which leaves the homeowner roughly 3,800 better off over five years if the new deal is still available. The calculator shows these exact figures for your inputs.
The costs of remortgaging
| Cost | What it is | Often avoidable? |
|---|---|---|
| Early repayment charge | Fee for leaving a deal early | Yes, by switching when the deal ends |
| Product or arrangement fee | Charge for the new deal | Sometimes, with a higher rate |
| Valuation | Lender checks the property | Often free |
| Legal fees | Solicitor work for the switch | Often free on remortgage deals |
| Broker fee | Adviser's charge | Some are free |
| Exit or administration fee | Closing your old mortgage | No, but usually small |
A lower rate with high fees can cost more than a slightly higher rate with none. This is why the calculator takes every cost into account and turns it into a break-even.
Other things to consider
- Fixed or tracker. A fixed rate gives certainty but usually carries an early repayment charge. A tracker may have none but moves with the base rate.
- Overpayment limits. Many deals allow overpayments up to a percentage of the balance each year without a charge.
- Your loan-to-value. A lower loan-to-value often unlocks better rates, and your home may have risen in value.
- Portability. If you may move, check whether the deal can go with you.
- Advice. A broker can search the market, and an adviser must assess whether a product suits you.
Planning ahead for the end of your deal
The best time to think about a remortgage is well before your deal ends. Most lenders let you secure a new deal some months ahead, and many let you swap to a better product if rates fall before your start date. That removes the risk of drifting onto a higher standard variable rate, and it can avoid an early repayment charge entirely. Put the end date of your deal in your diary, and ask your lender how far ahead you can book.
When you compare options, look at the total cost over the length of the deal, not just the rate. A deal with a high fee and a low rate can cost more than one with a slightly higher rate and no fee, particularly on a small balance. The calculator turns every fee and any cashback into a break-even so that you can compare like with like.
Common mistakes
- Letting the deal end and drifting onto the standard variable rate.
- Judging by the rate alone. Fees and charges change the answer.
- Ignoring the early repayment charge.
- Adding fees to the loan without noticing the interest.
- Assuming the example figures are yours. Use real quotes.
Related refinance tools and guides
This calculator is one of a set of free refinance tools on Utiliby. Depending on what you are deciding, these may help next.
- Mortgage Refinance Calculator Canada: the version for another country.
- Home Loan Refinance Calculator (Australia): the version for another country.
- Home Loan Refinance Calculator India: the version for another country.
- Mortgage Refinance Calculator: the US version, with a full savings view.
- Refinance Break-Even Calculator: payback month.
For background reading:
Privacy, accuracy and limits
The calculator runs entirely in your browser. The figures you enter are not sent to a server and are not stored, and reloading the page returns the example. The default rates and fees are illustrations. Interest is modelled monthly, stamp duty does not apply to a remortgage, and a lender decides whether to offer you a mortgage. Confirm every number with your lender or adviser before you decide.
Frequently asked questions
What is a remortgage?
Remortgaging means replacing your current mortgage with a new one on the same property, either with your current lender (often called a product transfer) or with a different lender. People do it to get a lower rate, change the term, release equity or move off a standard variable rate.
When should I remortgage?
Usually when your deal is about to end, because you can often move to a new deal without a charge and avoid the standard variable rate. You can look for a new deal several months before the end date, and the Wait tab shows the cost of switching early.
What is an early repayment charge (ERC)?
It is a fee a lender charges if you repay a mortgage or switch before the end of its deal period. It is often a percentage of the amount you repay, and the percentage commonly falls each year of the deal. Your mortgage offer states yours.
How do I find my early repayment charge?
Look in your mortgage offer or illustration, or ask your lender for a redemption statement. The statement shows the exact figure on a given date. Enter it as a percentage of your balance in the calculator.
Is it worth paying an ERC to switch?
Sometimes. If the monthly saving is large and you will keep the new deal for years, the saving can repay the charge. Enter your figures and the calculator shows the break-even month and compares paying the ERC with waiting until your deal ends.
What fees are there when I remortgage?
Common costs are a product or arrangement fee, a valuation fee, legal fees, a broker fee and a charge from your old lender for closing the account. Many remortgage deals offer free valuations and free legal work, so compare the whole cost, not just the rate.
Can I add fees to the mortgage?
Often you can, especially the product fee. It avoids paying cash up front but you pay interest on it for the term. Choose the option in the calculator to see the effect on the break-even.
What is a standard variable rate?
It is the rate your lender moves you to when your deal ends, unless you choose another deal. It is often higher than the best deals available, which is why many people remortgage as a deal ends.
What is a product transfer?
A product transfer moves you to a new deal with your existing lender. It is usually quicker and has fewer checks, but you should still compare it with the rest of the market.
Does remortgaging affect my credit file?
Applications can leave a record on your credit file, and a lender will assess your income and spending. Check with a broker or lender how a remortgage may affect you.
Should I overpay my mortgage instead?
It depends on your rate, your other debts, savings and any overpayment limits. The calculator lets you keep paying your current amount on the new rate, which shows how much sooner you could clear the mortgage.
Is the break-even the same as the time to recover the fees?
Yes. It is the month when your savings have repaid the charges and fees, less any cashback. If you expect to move or remortgage again before then, switching may not pay.
What does cashback do?
Some deals pay cashback on completion. It reduces the net cost of switching, but check the rate and fees, because a deal with cashback may cost more elsewhere.
Can I remortgage to borrow more?
You can ask a lender for further borrowing, but this calculator compares the same balance on a new deal. For releasing equity, a lender will look at your income, the value of the home and your other commitments.
How accurate are the default figures?
They are examples only. Replace each field with the figures from your offer, your redemption statement and a mortgage illustration.
Is my information private?
Yes. The calculator runs in your browser. Nothing you enter is sent to a server, saved or shared, and reloading the page resets it.
Is this remortgage calculator free?
Yes. It is a free online calculator with no sign-up, trial or limit. You can print or download the results.
Sources and further reading
- MoneyHelper, "Remortgaging: what it is and how it works" and "Early repayment charges" (moneyhelper.org.uk).
- Financial Conduct Authority, "Mortgages: changing your mortgage deal" and consumer guidance on mortgage charges (fca.org.uk).
- GOV.UK, guidance on buying and owning a home, including mortgage costs (gov.uk).
- Which?, Remortgaging guides (which.co.uk).
Sources were consulted in October 2026. Standards and rules can change, so always check the official page for your situation.