M
About

A calculator that respects you

Why we built this

Most mortgage calculators show you a monthly payment and call it a day. But a 25-year mortgage isn't a monthly payment — it's a date in your future. We wanted to make that date tangible. Tap "Friday, 12 March 2049" and suddenly overpayments stop being abstract maths and become "do I want to be free three years earlier or not?"

The Lifestyle Swap is the bit we love most. It started as a bit of fun and turned out to be the most powerful nudge we'd ever built. Knowing that one daily coffee equals roughly two and a half years of mortgage feels different to knowing it costs £82 a month.

Our calculators

We've built four free tools to help you at every stage of your mortgage journey:

  • Affordability Calculator — Find out how much UK lenders would realistically offer you based on your income, outgoings and deposit.
  • Repayment Calculator — See your monthly payment for any loan amount, interest rate and term, plus the total interest you'll pay.
  • Overpayment Calculator — Our favourite. Discover your Freedom Date and watch it jump forward as you add overpayments using the Lifestyle Swap.
  • Stamp Duty Calculator — Calculate SDLT (England), LBTT (Scotland) or LTT (Wales) with band-by-band breakdowns, first-time buyer relief and additional property surcharges.

Common questions

We use the same formulas the banks do — a standard amortisation schedule with monthly compounding. The Freedom Date is calculated month-by-month from today. That said, real mortgages may calculate interest daily, charge fees, or have early-repayment penalties, so always treat the result as guidance and check your specific deal.
Most fixed-rate mortgages allow you to overpay up to 10% of the outstanding balance each year without penalty. Going beyond that during the fixed period can trigger an Early Repayment Charge (typically 1–5%). Tracker and standard variable rate mortgages usually allow unlimited overpayments. Always check your offer.
Generally, if your mortgage rate is higher than the after-tax return you could realistically get from investing, overpaying wins — and it's risk-free. But pension contributions get tax relief that often beats both. The honest answer: it depends on your rate, your tax band, your risk tolerance and how much liquidity you want. Worth a chat with an adviser before pouring large sums in.
Yes — we use the rates in force as of April 2026: SDLT bands reintroduced 1 April 2025; LBTT with ADS at 8% (December 2024 change); and LTT including the December 2024 higher-rate band restructure for additional properties.
Because we hate sign-ups too. Nothing about your inputs is sent to a server, stored, or sold. The whole calculator runs in your browser. The only data we collect is anonymous traffic stats so we know which calculators people find useful.
Two non-intrusive Google ads per page. We picked the placements deliberately so they never get in the way of the calculator itself. If ads ever feel pushy to you, please tell us — that means we got the balance wrong.
Brilliant. Drop us a line via the contact link below — we're always tweaking.
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Disclaimer

The information on this site is for guidance only and does not constitute financial advice. Mortgage decisions should always be made with the help of a qualified, regulated mortgage adviser. Tax rates and rules change — while we keep this site updated, we can't guarantee perfect accuracy. We take no responsibility for decisions made based on these calculations. If you spot something wrong, please let us know.

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