Transparency
How we estimate home values
Most online valuations are a black box. Ours is not. Here is exactly how our house value calculator works, so you can judge for yourself how much to trust the number.
The short version
We take what you paid for your home and uplift it by how much average prices have risen in your local authority since you bought, using the official HM Land Registry House Price Index. That is the whole idea: no magic, just public data brought together honestly.
Step by step
1. We find your area from your postcode
When you enter your postcode, we look up which local authority it sits in using the open postcodes.io service. We do not store your postcode, and we never ask for your address or an email to see the result.
2. We measure how your area’s prices have moved
HM Land Registry publishes an average sold price for every local authority, every month, going back to 1995. We compare the average price in the month you bought with the latest figure to get your area’s growth factor.
3. We apply that growth to what you paid
Your estimated value is simply what you paid multiplied by that growth factor. If homes in your area are up 40% since you bought, your estimate is your purchase price plus 40%.
4. We add today’s mortgage picture
We also show what a home at that value would cost per month on a 25-year repayment mortgage at current rates, because what a home is worth and what it costs to buy are two different, useful things.
Why it is a guide, not a valuation
Local authority averages cannot see your specific home. A renovated house and a tired one on the same street sold for very different prices, and your exact road, plot, and any improvements all matter. Only a RICS surveyor or a local estate agent can value those. Treat our number as a well-informed starting point, not a formal valuation.
Where the data comes from
House price data is from the HM Land Registry UK House Price Index, updated monthly. Postcode lookups use postcodes.io. We refresh our figures each time new Land Registry data is published.
Contains HM Land Registry data © Crown copyright and database right. Licensed under the Open Government Licence v3.0. Covers England and Wales. Not financial advice or a formal property valuation.