Remortgage Calculator
See if switching your mortgage saves money. Compare your current deal with new rates, weigh up 2-year fix vs 5-year fix vs tracker over 5 years, and check how your LTV ratio affects the rates available to you.
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How to Use This Calculator
Should I Remortgage? tab
Enter your current mortgage balance, current interest rate (check your latest statement or lender's website), remaining term, and the new rate you've been offered. Include all fees: arrangement fee, valuation, and legal costs. The calculator shows your monthly saving, net saving after fees over the deal period, and how many months until you break even.
Deal Comparison tab
Compare three common deal types side by side: 2-year fixed, 5-year fixed, and tracker. Enter rates and fees for each. The calculator models the total cost over 5 years including revert-to-SVR periods — for a 2-year fix, it assumes you remortgage again after 2 years (two deals plus 1 year on SVR). This shows the true cost beyond just the headline rate.
LTV Impact tab
Enter your property value and mortgage balance to see your Loan-to-Value ratio. The calculator shows which rate band you fall into (60%, 75%, 85%, 90%, 95%) and exactly how much equity you need to reach the next lower band for better rates. Each band drop typically saves 0.15-0.30% on your rate.
Share your result
Every input is encoded in the URL. Click Share to send your exact scenario to a partner, mortgage broker, or save it for later.
The Formula
Remortgage savings are calculated using the standard mortgage repayment formula:
Where r = annual rate / 12 (monthly rate), n = remaining term in months
Monthly Saving = Current Payment − New Payment
Gross Saving = Monthly Saving × Deal Period (months)
Net Saving = Gross Saving − Total Fees (arrangement + valuation + legal + ERC)
Break-even Months = Total Fees / Monthly Saving
LTV = (Mortgage Balance / Property Value) × 100
The key insight for remortgaging is the break-even point. Even if a new deal saves you money each month, upfront fees mean it takes several months before you are genuinely better off. A good rule of thumb: if you break even within the first year of the new deal, it is almost certainly worth switching.
For deal comparison, total cost over 5 years matters more than the headline rate. A lower-rate deal with a £2,000 fee may cost more overall than a slightly higher rate with no fee, especially on smaller balances.
Example
Sarah — Teacher, 38, Bristol
Sarah has a £200,000 mortgage at 6.2% SVR with 22 years remaining. Her 2-year fixed deal ended 6 months ago and she rolled onto her lender's SVR. She has been offered a 5-year fix at 4.3% with total fees of £1,500 (£999 arrangement fee + £0 valuation + £500 legal).
Should I Remortgage? tab
Sarah saves £217 per month and recoups her £1,500 in fees in just 7 months. Over the 5-year deal she saves £11,523 net. The remortgage is clearly worthwhile — she was losing over £200/month by staying on the SVR.
Key lesson
If your fixed deal has ended and you have rolled onto your lender's SVR, remortgaging should be your top financial priority. SVRs are typically 7-8% while competitive deals are around 4-5%. On a £200,000 mortgage, that difference costs over £200 per month.