Property & Mortgage Calculators UK
Reviewed against official UK sources by the FreeCalculator editorial team Methodology Editorial policy
From your first mortgage to selling up, these tools cover the whole journey of buying, owning and moving home in the UK. Each one shows its working — the formula, a worked example and the current rates behind the result.
Pick the stage you’re at below. Not sure where to begin? Most buyers start with affordability; most homeowners start with overpayments or remortgaging.
Planning a purchase
Before you buy, three numbers matter most: how much you can borrow, how much you’ll need up front, and what the home will really cost. Start with the Affordability Calculator to gauge your budget, then use the Mortgage Calculator for the monthly repayment. Add stamp duty and every other upfront cost with the True Cost tool so nothing catches you out on completion day.
Mortgage Calculator
Estimate your monthly mortgage repayment, total interest and total cost over the full term.
Open calculatorAffordability Calculator
Get an indicative idea of how much you could borrow based on your income and deposit.
Open calculatorStamp Duty Calculator
Calculate Stamp Duty Land Tax (SDLT) in England & NI, with first-time buyer relief.
Open calculatorLoan-to-Value Calculator
Work out your LTV ratio and equity, and what it takes to reach a lower, better-rate band.
Open calculatorTrue Cost of Buying a House
Add up every cost of buying — deposit, tax, fees, moving and first-year running costs.
Open calculatorManaging your mortgage
Already own your home? Small changes can save thousands. Use the Overpayment Calculator to see how paying a little extra shortens your term, check the impact of a higher rate with the Rate Rise Calculator, and compare the cost of switching deals with the Remortgage Calculator when your fixed period ends.
Mortgage Overpayment Calculator
See how overpaying — monthly or a lump sum — cuts your mortgage term and total interest.
Open calculatorMortgage Rate Rise Calculator
See how a change in interest rates would affect your monthly payment, with a stress-test table.
Open calculatorRemortgage Calculator
Compare staying put vs switching deal — including ERC, fees and cashback — and find your break-even.
Open calculatorHelp to Buy Repayment Calculator
Estimate the cost to repay a Help to Buy equity loan — a share of your home’s current value.
Open calculatorSelling or moving on
When it’s time to move, work out what you’ll actually walk away with. The House Sale Profit Calculator estimates your net proceeds after the outstanding mortgage, estate-agent and legal fees. Buying again? Revisit the True Cost of Buying and Remortgage tools to plan the next move.
House Sale Profit Calculator
Estimate the cash you keep after selling — repaying the mortgage and paying selling costs.
Open calculatorRemortgage Calculator
Compare staying put vs switching deal — including ERC, fees and cashback — and find your break-even.
Open calculatorTrue Cost of Buying a House
Add up every cost of buying — deposit, tax, fees, moving and first-year running costs.
Open calculatorGuides
In-depth, plain-English guides that go deeper than the calculators.
How mortgage repayments are calculated
The formula behind your monthly payment, why early payments are mostly interest, and how the rate, term and overpayments change what you pay.
Read guide →How much deposit do I need?
The realistic minimum, how deposit size changes your rate and monthly payment, and how long it takes to save — with first-time buyer boosts.
Read guide →Should I overpay my mortgage?
What £50–£200 a month actually saves, lump sums vs monthly, the 10% rule and early repayment charges — and when saving beats overpaying.
Read guide →Frequently asked questions
- Which property calculator should I use first?
- If you’re planning to buy, start with the Mortgage Affordability Calculator to see roughly how much you could borrow, then the Mortgage Calculator for the monthly repayment. If you already own your home, start with the Overpayment or Remortgage calculator.
- Are these figures up to date for 2026/27?
- Yes. Stamp duty (SDLT, LBTT and LTT), tax thresholds and interest-rate context come from official UK sources and are dated on each calculator page, with a link to the source so you can check.
- Do the calculators include stamp duty and fees?
- The True Cost of Buying a House Calculator brings the deposit, stamp duty, and legal and mortgage fees together in one place. The standalone Stamp Duty Calculator covers England, Scotland and Wales separately.
- Can a calculator tell me whether I’ll be approved for a mortgage?
- No. These tools give reliable estimates to help you plan, but lenders assess affordability using your full income, outgoings, credit history and their own criteria. Always check a lender’s illustration before committing.
- How accurate are the results?
- The maths is tested against published examples, and every rate is sourced from GOV.UK, HMRC or the Bank of England. Results are estimates for guidance — your actual figures depend on your lender and circumstances.
Results are estimates for guidance only and are not financial advice. See each calculator page for its worked example, sources and the date its rates were last verified.