SFoverasking

How the estimate works

Where the sale prices come from

We work from closed sales, homes for sale with their asking prices, home facts and photos, and public property records. Every listing shows when it was last updated. Asking prices are not sale prices, and a home shown for sale may no longer be available.

A sale counts toward estimates only when it belongs to a single San Francisco property of the same type, at the same location and with the same unit. Homes we can't tie to one property stay browsable without an estimate. When two records describe the same closing, the closing price wins over a price we inferred.

Co-ops and below-market-rate homes are identified from city records, even when a listing calls them condos. They never enter the market-rate estimate. Their pages show recent sales of the same kind instead, and so do other homes we can't tie to a property.

For older sales, we infer the price from public tax records. Under Proposition 13, when a home changes hands its assessed value resets to the purchase price and then grows by at most 2% a year. So when a parcel's assessed value jumps in the year after a recorded sale, that new value, divided back by the inflation since the sale, is the sale price.

Transfers that don't trigger reassessment (into a trust, between spouses, parent to child) are excluded on purpose, because they are not market sales. Partial-interest transfers are excluded too.

When a home has changed hands but its price isn't public yet, the property page shows the date as price pending. Those transfers are never used as comps, and the previous owner's assessed value is never treated as a price.

Freshness and missing details

Recent closed sales arrive within weeks. Prices inferred from tax records lag 7 to 19 months, because the county publishes its roll once a year. The time adjustment below brings every price to today's level, and listing pages show when they were last updated.

A sold listing's photos and home facts may reflect a later relisting rather than the home's condition when it sold. Some listings have no photos.

Asking prices

A sale's asking price comes from that home's own listing history, matched to the sale by its listing, closing date and sale price. The final asking price is the last one advertised before the home went pending or closed; the first asking price is where the listing started, so a gap between them is a price cut. Of the 7,201 sales in the last year, 5,249 have a verified asking price.

The rest keep their state. "No asking price" means the history shows no asking price in that sale's cycle, often a home that sold without a public listing. "Unclear" means the history has conflicting events on the days that matter. Neither ever counts toward an over-asking figure, and a previous sale price or a later listing's asking price is never used as that sale's asking price.

Choosing comps

For a given home we look for sales of the same type (condo or single-family) within 0.35 miles and 18 months, widening gradually to 3 miles and 36 months only if we find too few. Each candidate gets a similarity score that multiplies together:

Every sale inside the search circle is ticked by default, and the estimate weighs each one by its score, so the closest and most similar sales count most. In testing on the 3,653 sales of the last year, using every sale in the circle beat using only the eight best matches: 13.1% median error against 13.5%. Sales with no size on record start unticked when the home's size is known, since the per-square-foot estimate can't use them. Untick any sale in the table, or click it on the map, and the estimate recalculates in your browser.

On a home's own page you can set the search yourself: drag the circle on the map to change how far out we look, and the strip of sales under it to change how far back. A search you draw keeps the 500 closest sales. The map is San Francisco itself, with its streets, parks and shoreline, so you can see which side of a park, a freeway or the bay a sale sits on.

Only closed sales count. A home that is for sale right now is left out, even if it sold earlier and is back on the market: its asking price is what the seller hopes to get, not what a buyer paid. Listings show you what is on the market; they never move the estimate.

Time adjustment

We compute a monthly median $/sqft for condos and for houses from the combined, deduplicated sales. A comp's price is multiplied by (index today รท index in its sale month), smoothed over three months and clamped so a thin month can't swing things wildly.

The number

When the subject home has a known square footage and at least three ticked comps do too, the estimate is the similarity-weighted median adjusted $/sqft times the subject's square footage. Otherwise we fall back to the weighted median adjusted sale price. Confidence comes from how many comps there are and how closely they agree: high with six or more whose middle half spans less than 15%, medium with three or more within 30%, low otherwise. A house tops out at medium: in testing, the houses that cleared the high bar missed by a median 17%, against 13% for medium ones.

The range comes from testing. We estimated each of the 3,653 closed sales so far in 2026 from the other sales, leaving its own out, and measured how far the actual price landed from the estimate. The range runs from the 10th to the 90th percentile of those misses for the home's confidence level and type, so about 8 in 10 sales land inside it: from 19% below to 21% above the estimate for a high-confidence condo, up to 35% below to 35% above for a low-confidence house. Houses vary more than condos, and a house that misses has usually sold below the estimate. Fitted on half of the sales and checked on the other half, the range held 78% to 82% of prices.

Over or under asking

When a home is for sale, its estimate uses its asking price too, and the asking price sits beside it: an estimate of $1,100,000 on a home asking $1,000,000 reads as 10% over asking.

We take the ticked comps with a verified asking price, find how far over (or under) it they sold, weighted the same way as the estimate, and apply that to this home's asking price; it needs at least three such comps. For a condo, that is the estimate. For a house, the estimate blends it with the estimate from comps alone (their geometric mean), because the blend comes closer than either. We tested this on 1,822 sales listed between April and October 2026, each priced as of the day its final asking price was set, using only the sales that had closed by then. The estimate was off by a median 4.8% for condos and 9.8% for houses, against 11.8% and 12.3% for the comps alone.

Its range is fitted the same way, on those sales, so about 8 in 10 sold inside it. A condo's confidence, and so its range, depends on how closely the comps agree on how far over asking they sold: within 6 points for high confidence (from 3% below to 11% above the estimate), more than 15 points apart for low (9% below to 25% above). A house's range runs from 16% below to 19% above at medium confidence and 17% below to 30% above at low.

What the owners paid

When a listed home has an earlier sale on record, its page shows that price and the same price grown 2% and 3% a year, roughly what owners who bought then hope to get back. It is a likely floor for houses, not for condos. In each verified sale's own price history from the last year, 254 houses were listed below what their sellers had paid, and 76% of them still sold for at least that much. Of 586 condos listed below the purchase price, 29% got back to it, and 27% of all condo sales closed below the previous price. Our sale records for earlier owners start in 2015, so many listed homes have no earlier sale on record.

Market and neighborhood figures

The market page and each neighborhood page show houses and condos over the twelve months to the newest sale and in the latest complete month: how many closed, the median and average sale price and the price per square foot. A month counts once all of it is in, and a month's prices need at least five sales. We lead with medians, because one record sale moves an average far from what a typical home sells for: in Pacific Heights a single $56 million sale lifts the average house price well above the median.

How far over asking homes sold, how many sold after a price cut, and how many days they took to go into contract, come only from sales whose asking price we verified against that sale's own listing history. A figure needs at least five such sales; until then it reads "too few yet". Days on market run from the day a home was listed to the day it went pending. A home for sale we can't tie to a property is placed in the neighborhood most of the homes around it belong to.

What this is not

It is not an appraisal, not a broker price opinion, and it knows nothing about condition, views, renovations, HOA health, or what the listing agent is doing with the price. Use it to sanity-check a list price and to ask better questions. Then talk to a human who has walked the property.