Remodel Estimator › Accuracy
Tested November 2026
How accurate is this?
How close our "value today" figure came on about 93,154 real California single-family sales that the model had never seen, and when we show a range.
Budget estimate, not a bid, appraisal, or insurance claim valuation. The home value figure is not an appraisal or a broker price opinion. Pilot.
How we test it
We took recorded single-family sales in six California counties and, one county at a time, set that county aside, built the model from the others, and then estimated every home in the county we set aside. So each figure below is how the model did on homes, and on a county, it had not seen.
- Typical error: half of the estimates missed the sale price by less than this, half by more.
- Likely range: when we show one, it is built to hold about half of sale prices for homes like yours (a central 50% range). In the tests, 52% to 60% of sales fell inside it depending on what the estimate knew (46% to 75% county by county).
- Low confidence: if the likely range for a home would be wider than about ±15% (high more than 1.35 times low), we do not show it. We show the estimate marked "Low confidence" and ask for the home's size or what you paid and when, the two facts that narrowed ranges in our tests. Adding a fact never widens the range.
- Shown a range: the share of homes that got a likely range rather than "Low confidence". Typical range: how wide the shown range usually was.
The more you tell the estimator, the closer it gets. With only an address it knows your neighborhood, not your house. Adding the home's size helps most. In Los Angeles County and San Francisco, where the county sale records are licensed for reuse, it also uses recent nearby sales of similar homes: there the typical error with home facts was 12.0% in the City of Los Angeles and 12.2% in San Francisco.
What the estimate knew
| Estimate based on | Sales tested | Typical error | Within 10% | Shown a range | Inside the range | Typical range |
|---|---|---|---|---|---|---|
| Address only | 93,154 | 17.1% | 32% | 32% | 56% | ±13% |
| With the home's size | 80,269 | 13.8% | 39% | 54% | 52% | ±12% |
| With size and nearby sales (Los Angeles County, San Francisco) | 79,683 | 10.4% | 49% | 68% | 60% | ±10% |
| With what you paid and when | 11,529 | 11.1% | 46% | 50% | 56% | ±12% |
| With what you paid and nearby sales | 11,228 | 10.7% | 48% | 74% | 52% | ±10% |
By county
| County | Sales tested | Typical error | Within 10% | Shown a range | Inside the range | Typical range |
|---|---|---|---|---|---|---|
| San Francisco | 1,542 | 23.4% | 22% | 1% | — | — |
| City of Los Angeles | 6,909 | 18.9% | 29% | 25% | 53% | ±13% |
| Sonoma County | 4,965 | 14.7% | 36% | 5% | 69% | ±14% |
| Alameda County | 12,866 | 17.6% | 30% | 0% | — | — |
| Riverside County | 40,144 | 14.1% | 37% | 66% | 57% | ±13% |
| San Diego County (check) | 26,728 | 23.3% | 24% | 4% | 45% | ±13% |
| County | Sales tested | Typical error | Within 10% | Shown a range | Inside the range | Typical range |
|---|---|---|---|---|---|---|
| San Francisco with nearby sales | 1,542 | 12.2% | 43% | 34% | 60% | ±13% |
| City of Los Angeles with nearby sales | 6,893 | 12.0% | 44% | 71% | 50% | ±11% |
| Sonoma County | 4,965 | 12.4% | 42% | 33% | 70% | ±13% |
| Alameda County | Not enough sales to test (no home sizes in these records) | |||||
| Riverside County | 40,144 | 10.5% | 48% | 80% | 54% | ±12% |
| San Diego County (check) | 26,725 | 21.0% | 26% | 26% | 45% | ±12% |
San Diego County is a check only: its prices are assessor values reset at sale, which are rougher than sale prices, so it is not used to set the model. Prices in Los Angeles and San Francisco are also assessor values reset at sale; Alameda prices come from transfer tax; Riverside and Sonoma are recorded sale prices.
By price
| Estimated value | Sales tested | Typical error | Within 10% | Shown a range | Inside the range | Typical range |
|---|---|---|---|---|---|---|
| Under $700,000 | 30,509 | 14.2% | 38% | 60% | 59% | ±13% |
| $700,000 to $1.5 million | 54,201 | 18.0% | 30% | 21% | 52% | ±13% |
| $1.5 million and up | 8,444 | 25.9% | 21% | 0% | — | — |
| Estimated value | Sales tested | Typical error | Within 10% | Shown a range | Inside the range | Typical range |
|---|---|---|---|---|---|---|
| Under $700,000 | 28,958 | 11.1% | 46% | 79% | 52% | ±12% |
| $700,000 to $1.5 million | 44,801 | 14.3% | 38% | 49% | 53% | ±12% |
| $1.5 million and up | 6,510 | 19.7% | 28% | 19% | 51% | ±13% |
Higher-priced homes vary more, so they get a range less often. If you tell us what you paid and when, we bring that price forward with the FHFA home price index and combine it with the other figures; when the two disagree a lot, the weights follow what was more reliable in tests. On 11,529 homes that had sold before, the typical error was 11.1%, with 46% within 10%.
Across California
Estimated share of addresses that get a likely range, for a home of typical size for its area (census tracts weighted by recent home loans). The other addresses see the estimate marked "Low confidence" until more is known.
| Estimated value | Address only | With the home's size |
|---|---|---|
| Under $700,000 | 66% | 86% |
| $700,000 to $1.5 million | 36% | 67% |
| $1.5 million and up | 5% | 30% |
All 58 counties
| County | Address only | With the home's size |
|---|---|---|
| Alameda County | 17% | 55% |
| Alpine County | 0% | 100% |
| Amador County | 36% | 85% |
| Butte County | 53% | 88% |
| Calaveras County | 53% | 69% |
| Colusa County | 76% | 85% |
| Contra Costa County | 35% | 60% |
| Del Norte County | 48% | 86% |
| El Dorado County | 13% | 72% |
| Fresno County | 73% | 84% |
| Glenn County | 86% | 100% |
| Humboldt County | 57% | 83% |
| Imperial County | 80% | 96% |
| Inyo County | 29% | 55% |
| Kern County | 73% | 92% |
| Kings County | 95% | 97% |
| Lake County | 42% | 87% |
| Lassen County | 0% | 61% |
| Los Angeles County | 37% | 62% |
| Madera County | 47% | 100% |
| Marin County | 5% | 27% |
| Mariposa County | 71% | 100% |
| Mendocino County | 80% | 89% |
| Merced County | 87% | 99% |
| Modoc County | 0% | 100% |
| Mono County | 17% | 46% |
| Monterey County | 53% | 74% |
| Napa County | 42% | 66% |
| Nevada County | 15% | 68% |
| Orange County | 15% | 40% |
| Placer County | 32% | 79% |
| Plumas County | 30% | 91% |
| Riverside County | 70% | 87% |
| Sacramento County | 65% | 88% |
| San Benito County | 86% | 93% |
| San Bernardino County | 65% | 86% |
| San Diego County | 25% | 54% |
| San Francisco County | 4% | 28% |
| San Joaquin County | 69% | 93% |
| San Luis Obispo County | 18% | 69% |
| San Mateo County | 15% | 48% |
| Santa Barbara County | 47% | 61% |
| Santa Clara County | 16% | 48% |
| Santa Cruz County | 12% | 44% |
| Shasta County | 64% | 92% |
| Sierra County | 0% | 0% |
| Siskiyou County | 43% | 76% |
| Solano County | 72% | 90% |
| Sonoma County | 43% | 68% |
| Stanislaus County | 78% | 92% |
| Sutter County | 90% | 97% |
| Tehama County | 55% | 89% |
| Trinity County | 58% | 100% |
| Tulare County | 78% | 91% |
| Tuolumne County | 10% | 78% |
| Ventura County | 45% | 72% |
| Yolo County | 68% | 88% |
| Yuba County | 84% | 94% |
Limits
- We could test only the six counties with free sale records. Other counties use the same method and should do about as well as the address-only figures above, but we cannot measure them yet.
- Unusual homes (very large, very small, hillside, waterfront, recently rebuilt) miss by more. So do higher-priced homes.
- Rural homes: estimates used to run about 7% high; an adjustment for how built-up the area is and Census home values brought that to about 3% on held-out sales.
- Condition and remodel year are what you tell us; we adjust for them conservatively and widen the range a little.
- This is a planning figure for weighing a remodel. For a sale, refinance, insurance or a legal matter, use a licensed appraiser.
Method and data: HMDA public loan records (CFPB), FHFA house price indexes (quarterly and the monthly Pacific index), the FHFA Uniform Appraisal Dataset as a background check, Census ACS and Gazetteer, and county assessor and recorder records: Los Angeles County (eGIS Terms of Use), San Francisco (DataSF, PDDL 1.0), Sonoma, Riverside, Alameda and San Diego (testing only). Updated November 2026.