How Accurate Are Our Estimates?
Indicative estimate, not a formal valuation. Our ranges are a quick guide to what a home might be worth today, worked out from its last sale. A surveyor or estate agent who visits the property will give you a much better answer.
Latest results
We tested the estimates on 123,443 homes that sold between 28 August 2025 and 28 August 2026 and had sold before. For each one we estimated the price from its previous sale only, then compared it with what it actually sold for.
One in four estimates was more than 15.4% out, and one in ten more than 26.4%. We could make an estimate for 47.1% of all the homes sold in that year; the rest hadn't sold since 2014, had sold too recently, or didn't meet our checks.
By confidence level
| Homes | Median error | Within 10% | 1 in 10 more than | Inside range | |
|---|---|---|---|---|---|
| High | 29,587 | 6.7% | 66.0% | 21.9% | 79.9% |
| Medium | 60,969 | 8.1% | 58.5% | 26.3% | 80.2% |
| Low | 32,887 | 9.6% | 51.3% | 29.9% | 79.9% |
By time since the previous sale
| Homes | Median error | Within 10% | 1 in 10 more than | Inside range | |
|---|---|---|---|---|---|
| 0.5-2 years | 7,511 | 9.4% | 51.7% | 40.8% | 68.3% |
| 2-5 years | 34,731 | 6.8% | 65.3% | 22.6% | 80.4% |
| 5-10 years | 64,691 | 8.3% | 57.7% | 25.2% | 81.5% |
| 10+ years | 16,510 | 10.1% | 49.4% | 29.4% | 79.0% |
By property type
| Homes | Median error | Within 10% | 1 in 10 more than | Inside range | |
|---|---|---|---|---|---|
| Detached | 26,428 | 8.1% | 58.6% | 25.7% | 81.0% |
| Semi-detached | 36,702 | 7.9% | 59.6% | 24.9% | 81.6% |
| Terraced | 38,440 | 7.7% | 60.1% | 26.1% | 80.3% |
| Flat/maisonette | 21,873 | 9.3% | 53.1% | 30.9% | 76.0% |
How the estimates work
- We take the home's last sale price from HM Land Registry Price Paid Data.
- We move it in line with the UK House Price Index (UK HPI) for the local authority and property type, from the month it sold to the latest month published. Where there's no local series, we use the county, region or country, and lower the confidence.
- We put a range around it. The width comes from the test above: for each confidence level, it's the range that held 80% of real sold prices.
Confidence is lower when the last sale was a long time ago (or very recent, as quick resales are often renovated), when it was a new build or an unusual sale, when few homes sell in the postcode district, or when local prices have been jumping around.
We don't show an estimate for homes sold in the last 6 months, sales more than 20 years old, homes of type "other", or where the data doesn't support one. We can't see extensions, refurbishments, condition or the size of a home. A later version may use floor areas from Energy Performance Certificates; this one doesn't.
About this test
- Data: Full HM Land Registry Price Paid archive used by the site (11,808,428 sales, 2014-01-01 to 2026-08-28); UK HPI to Aug 2026.
- Only standard sales of houses and flats were tested. The ranges were set using half the homes and the results above measured on the other half, so they show how the method does on homes it hasn't seen.
- Uses today's (revised) UK HPI figures; live estimates use the latest provisional month, so real-world errors may be somewhat larger.
- Only homes with an earlier sale in the archive can be estimated; extensions, refurbishments and condition are not known to the model.
- Last run: 2026-10-27 16:45 (model A1).
Contains HM Land Registry data © Crown copyright and database right 2026. This data is licensed under the Open Government Licence v3.0. UK House Price Index data: HM Land Registry, Registers of Scotland, Land and Property Services Northern Ireland and the Office for National Statistics, to Aug 2026 (the latest 12 months are provisional and may be revised).