Tools

Property calculators

Twelve calculators we use in real conversations with buyers, sellers and landlords across London. They run entirely in your browser, so nothing you type is sent anywhere.

Instant valuation

An indicative value for your home in seconds, built from the real sold prices recorded near you by HM Land Registry.

Rent estimate

What your property could let for each month, from the ONS private rents series for your borough and property size.

Stamp duty calculator

Work out the SDLT due on an England or Northern Ireland purchase, band by band, including first-time buyer relief and the additional-property and non-resident surcharges.

Mortgage repayment calculator

Monthly repayment, total interest and a year-by-year amortisation summary for any loan amount, rate and term.

Affordability calculator

An indicative borrowing range from your income and deposit, and the purchase price it puts within reach.

Rental yield calculator

Gross and net yield on a London buy-to-let, with the income you actually keep once running costs and voids are deducted.

Buy to let stamp duty calculator

SDLT on an additional property including the 5% surcharge, plus the net yield once the tax is spread across your holding period.

Remortgage calculator

Your new monthly payment at a different rate, the saving it produces, and how long a product fee takes to pay back.

Mortgage overpayment calculator

How much sooner your mortgage clears, and how much interest you never pay, if you overpay monthly or in a lump sum.

Capital gains tax calculator

CGT on the sale of a second home or buy-to-let, after costs, improvements and the annual exempt amount.

Rent vs buy calculator

The cash cost of renting against owning over the years you plan to stay, and the year buying pulls ahead.

Lease extension calculator

An indicative premium for extending a leasehold flat, from the years remaining, the value of the flat and the ground rent.

Sources: mortgage rates are UK average quoted rates published by the Bank of England, September 2026, updated monthly. Sold price figures come from HM Land Registry Price Paid Data (© Crown copyright, Open Government Licence v3.0). Rents use the ONS Price Index of Private Rents. Tax bands follow HMRC guidance. Reference data only — no lender products, no advice.