Remortgage Calculator UK
Compare your current mortgage deal against a new one, factoring in product and legal fees, to see whether remortgaging actually saves you money — and how much.
Remortgaging is switching to a new deal — either with your current lender or a new one — usually when your fixed rate is ending and you’re about to roll onto an expensive standard variable rate. The potential saving is large: on a £200,000 balance, moving off an 8% SVR onto a 5% fix saves around £353 a month, or £8,500 over a two-year deal. But a remortgage isn’t free — there are product fees, sometimes legal and valuation costs, and the saving has to clear those before it counts. The real question this calculator answers isn’t “what’s the new rate”, it’s “does switching beat staying, once the fees are in“. It also weighs the two ways to switch: a quick product transfer with your existing lender, or a full remortgage to a new one. To model the underlying repayment, use the Mortgage Calculator.
Current mortgage
New remortgage deal
Fees and charges
Property value and LTV
Remortgage result
Estimated net saving over deal period
Calculating…
Calculating…
Current monthly payment
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New monthly payment
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Monthly difference
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Break-even point
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New mortgage balance
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New LTV
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What remortgaging saves — quick lookup
The left table shows the monthly saving from cutting your rate, by balance and by how far the rate falls — useful whether you’re coming off an SVR or simply onto a better fix. The right shows how quickly a typical product fee pays for itself. Both assume around 20 years remaining; the calculator above runs your exact figures.
| Balance | 6%→5% | 7%→5% | 8%→5% |
|---|---|---|---|
| £100k | £56 | £115 | £176 |
| £150k | £85 | £173 | £265 |
| £200k | £113 | £231 | £353 |
| £250k | £141 | £288 | £441 |
| £300k | £169 | £346 | £529 |
| Monthly saving | Break-even |
|---|---|
| £50/mo | 20 months |
| £100/mo | 10 months |
| £200/mo | 5 months |
| £350/mo | 2.8 months |
| £500/mo | 2 months |
Put the two together and the decision becomes clear. A £200,000 borrower coming off an 8% SVR onto a 5% fix saves £353 a month — and a £999 product fee pays for itself in under three months, leaving roughly £7,500 of net saving over a two-year deal. The bigger the balance and the steeper the rate drop, the more obviously worthwhile the switch. The fee only becomes a real consideration when the saving is small.
How remortgaging works
A remortgage replaces your existing mortgage with a new deal on the same property. Most people remortgage for one reason: their fixed or tracker deal is ending, and without action they’ll roll onto the lender’s standard variable rate (SVR) — typically the most expensive rate on offer. Remortgaging onto a fresh deal keeps the payment down. Others remortgage to release equity, change the term, or move to a better product mid-term, but the expiring-deal trigger is by far the most common.
The timing that matters
The window is everything. You can usually line up a new deal three to six months before your current one ends, with the new rate starting the day the old one expires — so there’s no gap on the SVR at all. Leave it too late and you spend months on the expensive variable rate while the application processes; start sensibly early and the switch is seamless. The single most expensive mistake in UK mortgages is doing nothing and drifting onto the SVR through inertia, because the lender has no obligation to chase you onto a cheaper deal.
The fees, and why they decide it
A remortgage can carry several costs, and the saving has to clear them to be worthwhile:
The good news is that many remortgage deals come with free valuation and free legals, especially product transfers, so the only real cost is the arrangement fee — and as the break-even table shows, that’s usually recovered within months on any meaningful saving. The fee genuinely matters only when the saving is marginal, or on a small balance where a £999 fee is a large slice of the benefit. The classic trap is choosing the lowest headline rate while ignoring a fat fee that wipes out the difference.
How LTV shapes the rate you’ll get
Since you took out the original mortgage, two things have probably changed: you’ve repaid some capital, and the property may have risen in value. Both lower your loan-to-value (LTV), which can drop you into a cheaper rate band at remortgage. A borrower who started at 90% LTV might be at 75% by the time they remortgage, unlocking a noticeably better rate. Overpayments accelerate this — every pound of extra capital repaid improves your LTV and your bargaining position at the next deal.
The early repayment charge warning
Remortgaging during a fixed period — rather than at its end — usually triggers an early repayment charge, often 1–5% of the balance. On a £200,000 balance, even a 2% ERC is £4,000, which can swallow any saving from a lower rate. Unless rates have fallen dramatically, it rarely pays to break a fix early. The sweet spot is remortgaging exactly as the deal ends, when ERCs have lapsed and you avoid the SVR. The FCA requires your ERC terms to be set out clearly in your mortgage paperwork.
Four worked examples
Real remortgage decisions, showing how the saving stacks up against the fees in each case.
Example 1 — Hannah (escaping the SVR)
£200,000 balance, drifted onto an 8% SVR
New 5% fix: £1,320/mo
Monthly saving: £353 · £999 fee clears in 2.8 months
Net saving over 2-year fix: £7,472
Hannah’s fix ended six months ago and she did nothing, so she’s been paying the SVR. Remortgaging onto a 5% fix cuts £353 a month — over £4,000 a year. Even with a £999 product fee, she’s ahead within three months and saves nearly £7,500 across the new two-year deal. Her only real cost was the half-year she spent on the SVR before acting; the lesson is to line the new deal up before the old one ends.
Example 2 — Greg (the fee that didn’t clear)
£90,000 balance, small saving, big fee
Product fee: £1,499
Break-even: ~33 months — longer than a 2-year fix
Verdict: fee-free deal wins, even at a higher rate
Greg’s balance is small and his rate cut modest, so his monthly saving is only around £45. A £1,499 fee would take nearly three years to recover — longer than the two-year deal lasts. For Greg, a fee-free deal at a slightly higher rate beats the low-rate-plus-fat-fee option. This is the case the break-even maths exists for: on small balances, the fee can completely reverse which deal is cheaper.
Example 3 — Dani (product transfer, no fuss)
£180,000 balance, staying with the same lender
No legal or valuation fee, minimal paperwork
Slightly higher rate than whole-of-market, but faster
Saving vs SVR: still substantial
Dani’s fix is ending and her lender offers a product transfer — a new deal with the same lender, no new affordability check, no legal work, completed in days. The rate is marginally higher than the best deal on the open market, but she avoids the cost and hassle of a full remortgage. For borrowers who value speed and simplicity, or whose circumstances have changed (making a fresh affordability check risky), a product transfer is often the pragmatic choice even if it’s not the absolute cheapest.
Example 4 — Marcus (tempted to break early)
£200,000 balance, 18 months into a 5-year fix
Tempting new deal: 4.8%, saving ~£80/mo
ERC to break early: ~3% of £200k = £6,000
Verdict: ERC dwarfs the saving — stay put
Marcus spots a cheaper rate and wants to switch immediately. But breaking his fix three years early triggers a £6,000 early repayment charge, while the lower rate only saves around £80 a month — it would take over six years just to recover the ERC. Unless rates collapse, breaking a fix early almost never pays. Marcus’s best move is to note the date his deal ends and line up a remortgage for then, when the ERC has gone.
Your three options when a deal ends
When your fixed or tracker deal expires, you have exactly three paths — and they differ enormously in cost and effort. Most people sleepwalk into the worst one simply by doing nothing. Knowing all three, and what each costs, turns the end of a deal from a trap into an opportunity. Here they are, from worst to best for most borrowers:
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1
Do nothing — roll onto the SVR
The default if you don’t act. You drift onto the lender’s standard variable rate, almost always the most expensive option, set at the lender’s discretion and free to rise at any time.
It’s the most expensive path and the most common, because it requires no action — which is exactly why lenders rely on it. There’s no penalty to leave the SVR, so there’s no reason to stay.
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2
Product transfer — switch within your lender
Move to a new deal with your existing lender. Usually no affordability re-check, no legal or valuation fees, and completed in days. The rate may be slightly higher than the open market’s best.
Ideal if you value speed and simplicity, or if your circumstances have changed in a way that might complicate a fresh affordability check elsewhere.
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3
Full remortgage — switch to a new lender
Move to a different lender and the whole market’s rates. Often the cheapest rate, frequently with free valuation and legals, but it needs a full application, affordability check, and a few weeks to complete.
Best when the saving is large enough to justify the effort, your finances are straightforward, and you want the genuinely lowest rate available.
The three paths on a £200k balance, 20 years left
Same balance, three very different monthly costs:
The difference between the worst path and the best is £353 a month — over £4,000 a year — on a perfectly ordinary mortgage. And the worst path is the one you end up on by accident. The whole skill of remortgaging is simply remembering to act: set a reminder for three to six months before your deal ends, compare a product transfer against the open market, and pick whichever wins after fees. It’s one of the highest-value hours of admin a homeowner ever does.
Why “lowest rate” isn’t always the answer
The deal with the lowest advertised rate isn’t automatically the cheapest. A rate of 4.6% with a £1,499 fee can cost more than 4.8% with no fee, especially on a smaller balance or a short two-year deal where there’s less time to recover the fee. The only way to compare properly is total cost over the deal period — rate plus fees — not the headline number. This is exactly where a remortgage calculation earns its keep: it strips away the marketing and shows the real all-in cost of each option.
Two scenarios that decide the switch
What if…
You added the fee to the loan?
What if…
You broke your fix early?
Key remortgage terms explained
Remortgaging has its own vocabulary, much of it about fees and timing. The ten terms below cover what you’ll meet when comparing deals and talking to a lender or broker.
- Remortgage
- Switching your existing mortgage to a new deal on the same property, with your current lender or a new one. Usually done when a fixed or tracker deal ends, to avoid rolling onto the standard variable rate.
- Standard variable rate SVR
- The lender’s default rate you roll onto when a deal ends if you do nothing. Set at the lender’s discretion and almost always the most expensive option. There’s no penalty to leave it, which is why staying on it is the most common avoidable mortgage cost.
- Product transfer
- Switching to a new deal with your existing lender. Usually no affordability re-check, no legal or valuation fees, and completed in days. The rate may be marginally higher than the open market’s best, but it’s fast and simple.
- Full remortgage
- Switching to a different lender and the whole market’s rates. Often the cheapest rate, frequently with free valuation and legals, but requires a full application, affordability check, and a few weeks to complete.
- Product / arrangement fee
- The headline fee for taking a mortgage deal, often £0 to £1,500+. The main cost to weigh against the saving. On large balances it’s quickly recovered; on small ones it can wipe out the benefit of a lower rate, so always compare total cost including fees.
- Early repayment charge ERC
- A penalty for leaving a deal during its fixed period — typically 1–5% of the balance, tapering each year. On a £200k balance, even 2% is £4,000, which usually dwarfs any saving from switching early. Lapses when the deal ends.
- Loan-to-value LTV
- Your remaining balance as a percentage of the property’s current value. Repaying capital and rising house prices both lower your LTV over time, which can drop you into a cheaper rate band at remortgage than you had originally.
- Free legals / free valuation
- Incentives many remortgage deals include, where the lender covers the conveyancing and property valuation costs. Common on remortgage products specifically (less so on purchases), they reduce the all-in cost of switching, sometimes to just the arrangement fee.
- Break-even point
- How long the monthly saving takes to recover the fees of switching. Fee ÷ monthly saving = months to break even. If that’s well within the deal length, the switch pays; if it’s longer than the deal, a fee-free option is usually better.
- Equity release (capital raising)
- Borrowing more when you remortgage, by increasing the loan against your built-up equity — for home improvements, debt consolidation, or other needs. Distinct from later-life “equity release” products. Raises your LTV and total interest, so use deliberately, not by default.
Five mistakes UK homeowners make remortgaging
Remortgaging is one of the highest-value pieces of admin a homeowner does — and these are the errors that waste that value, drawn from broker experience and the recurring r/UKPersonalFinance threads.
Doing nothing and drifting onto the SVR
The single most expensive mistake. When a deal ends, you roll onto the standard variable rate automatically — and the lender won’t chase you onto something cheaper. On a £200k balance, the SVR can cost £350+ a month more than a fresh deal. Set a reminder three to six months before your deal ends and line up the next one so there’s no gap.
Cost: £4,000+/year on the SVR Fix: start remortgaging 3–6 months before deal endsChasing the lowest rate while ignoring the fee
A 4.6% rate with a £1,499 fee can cost more than 4.8% with no fee, especially on a small balance or short deal. The headline rate is marketing; the total cost over the deal period is what matters. Always run rate-plus-fees, not just the rate — on smaller balances the fee can completely reverse which deal is cheaper.
Cost: picking the dearer deal by £1,000s Fix: compare total cost including all feesBreaking a fix early and eating the ERC
Spotting a cheaper rate and switching mid-fix usually triggers an early repayment charge of 1–5% of the balance — on £200k, potentially £6,000+. A modest monthly saving takes years to recover that. Unless rates have fallen dramatically, wait until your deal ends, when the ERC has lapsed, rather than paying to leave early.
Cost: £6,000+ ERC to save a little monthly Fix: remortgage at the end of the deal, not mid-fixOnly checking your own lender
A product transfer with your current lender is easy, but it’s rarely the cheapest deal available — your lender knows inertia is on their side. Compare the open market, or use a broker who can, before accepting a transfer. The transfer may still win on speed and simplicity, but you should know what you’re giving up to take it.
Cost: missing a cheaper whole-market rate Fix: compare your lender against the open marketRolling fees into the loan without thinking
Adding the product fee to the mortgage avoids paying it upfront, but you then pay interest on it for the whole term. A £999 fee added to a 20-year loan costs an extra £583 in interest. If you can spare the cash, pay fees upfront; only roll them in when liquidity is genuinely tight, and clear them with an overpayment when you can.
Cost: £583 extra interest on a £999 fee Fix: pay fees upfront if you can afford toFrequently asked questions
When should I remortgage?
The most common — and best — time is when your current fixed or tracker deal is ending, to avoid rolling onto the expensive standard variable rate. You can usually line up a new deal three to six months before the old one expires, with the new rate starting the day the old one ends, so there’s no gap.
You might also remortgage to release equity, change your term, or move to a better product. But remortgaging mid-deal usually triggers an early repayment charge, so unless rates have fallen sharply, the end of your deal is the moment to act.
How much can I save by remortgaging?
It depends on your balance and how far your rate falls. On a £200,000 balance with 20 years left, moving off an 8% standard variable rate onto a 5% fix saves around £353 a month — roughly £4,000 a year, or £8,500 over a two-year deal.
Even a one-point cut is worth having: on the same balance, 6% to 5% saves about £113 a month. The bigger your balance and the steeper the rate drop, the larger the saving. The calculator above shows your exact figures after fees.
What fees are involved in remortgaging?
The main one is the product (arrangement) fee, anywhere from £0 to £1,500 or more. There may also be valuation and legal fees, though many remortgage deals — especially product transfers — include these free. Your old lender may charge a small exit or deeds-release fee, and leaving a deal early triggers an early repayment charge.
The saving has to clear these to be worthwhile. As a rule, divide the total fees by your monthly saving to get the break-even point: if it’s comfortably within the deal length, switching pays.
What’s the difference between a product transfer and a remortgage?
A product transfer is a new deal with your existing lender — usually no affordability re-check, no legal or valuation fees, and done in days. The rate may be slightly above the open market’s best, but it’s fast and simple.
A full remortgage moves you to a different lender and the whole market’s rates, often cheaper, but it needs a full application, affordability check, and a few weeks. Compare both: the transfer wins on ease, the remortgage usually on rate. Pick whichever is cheaper after fees, unless you specifically value the speed of a transfer.
Should I pay the fee upfront or add it to the loan?
Pay it upfront if you can. Adding a fee to the loan means you pay interest on it for the whole term — a £999 fee added to a 20-year mortgage costs an extra £583 in interest over time.
Rolling it in only makes sense when cash is genuinely tight and you’d rather keep your savings liquid. If you do add it, consider clearing it with an overpayment when you can, to stop the interest accumulating. For most people with the cash available, paying upfront is the cheaper choice.
Can I remortgage if my fixed deal hasn’t ended?
You can, but it usually triggers an early repayment charge of 1–5% of the balance — on £200,000, even 2% is £4,000. That typically dwarfs any saving from a lower rate, so breaking a fix early rarely pays unless rates have collapsed.
The exception is if the saving is so large it clears the ERC quickly, which is unusual. For most people, the right move is to note the date your deal ends, line up a new deal three to six months ahead, and switch exactly when the ERC lapses.
Does remortgaging affect my credit score?
A full remortgage to a new lender involves a hard credit check, which leaves a footprint and can dip your score slightly and temporarily. A product transfer with your existing lender often doesn’t require a new check at all.
For a planned remortgage this is rarely a problem — one hard check around the time you switch is normal and recovers quickly. Just avoid making lots of credit applications in the same window, which can compound the effect and make lenders warier.
Do I need a solicitor to remortgage?
For a full remortgage to a new lender, yes — there’s conveyancing work to transfer the charge from one lender to another, though many deals include free legals so it costs you nothing. For a product transfer with your existing lender, usually no solicitor is needed, since the legal charge stays where it is.
This is one reason product transfers complete in days while full remortgages take weeks. If you want the lowest rate and don’t mind the wait, the legal work is worth it; if you value speed, a transfer skips it. For impartial guidance, MoneyHelper is a good independent source.
Related calculators
Remortgaging connects to the wider picture of what your mortgage costs and how fast you clear it. These calculators handle the adjacent decisions.
Methodology & sources
How the maths works
The calculator works out the monthly repayment on your current rate and on a new rate using the standard amortisation formula, applied to your remaining balance and remaining term. The monthly saving is the difference between the two payments. Multiplying by the deal length gives the gross saving, and subtracting total fees gives the net saving — the figure that determines whether switching is worthwhile.
The break-even point is the total fees divided by the monthly saving, expressed in months. If a fee is added to the loan rather than paid upfront, the calculator adds it to the balance, so you pay interest on it across the term. Figures assume a constant rate for the modelled period; your actual rate changes at each remortgage.
UK rules and conventions used
- Repayment formula: standard amortising loan, monthly compounding
- Monthly saving: current payment minus new payment on remaining balance/term
- Break-even: total fees ÷ monthly saving (in months)
- Product transfer: same lender, typically no legal/valuation fee
- Full remortgage: new lender, full affordability check, often free legals
- ERC: typically 1–5% of balance if leaving a deal during its fixed period
- Rates shown are illustrative to demonstrate the maths, not live market rates