How to compare Bay Area home prices without comparing the wrong homes

A lower city median can make a home search look simpler than it is. You might see a gap between San Mateo and Redwood City and assume that moving a few miles buys the same house for less. That is a useful question to investigate. The chart alone cannot answer it.

Start with a comparison you can describe in one sentence: “We are comparing single-family homes in these two cities, over the same sales period, before checking specific homes.” Then work from the city figures toward properties that resemble what you would actually buy.

1. Match the home type before comparing the price

Open the San Mateo–Redwood City comparison. Choose single-family homes or condos/co-ops consistently. If you choose both, read the two series separately; the tool does not turn their medians into one combined price.

A condo and a detached house can serve the same household while carrying different space, ownership and maintenance tradeoffs. Comparing their prices can help you choose between those options. It does not isolate what the city itself costs.

Also check geography. A citywide statistic describes the source's city boundary. A property's mailing-city label is not necessarily proof that it sits inside that municipality.

2. Read a median as a description of the homes that sold

The median is the middle of an ordered set of prices. It is not the price of an unchanging representative house. Redfin distinguishes the median of different homes selling in different periods from its separate repeat-sales home-price index. Our city comparison shows sale medians, not that index. Redfin's explanation.

Consider this purely hypothetical illustration, with five sales in each period:

• Period A: $1.0 million, $1.1 million, $1.2 million, $1.8 million and $2.0 million.
• Period B: $1.0 million, $1.1 million, $1.8 million, $1.9 million and $2.0 million.

The median rises 50%, from $1.2 million to $1.8 million. Suppose the lower prices represent smaller homes and the higher prices larger homes. Period B simply contains more of the larger homes. These invented sales do not establish that any individual house appreciated 50%.

When a real median moves, ask what changed in the homes sold before attributing the entire movement to the market.

3. Use price per square foot as another question

Redfin's sale-price-per-square-foot measure takes each included home's sale price relative to its reported approximate size, then reports the median. Homes without size information are excluded. Its sample can therefore differ from the full sales count. Redfin methodology.

Price per square foot helps you notice when a total-price difference might accompany a size difference. It does not equalize condition, layout, usable outdoor space, location or ownership obligations. A low figure still needs explanation.

Do not multiply a city median price per square foot by a candidate home's size and treat the answer as its valuation. Nor is the median of individual price-per-square-foot figures necessarily the median sale price divided by median size.

4. Compare the same dates, and watch overlapping windows

For city-level monthly market data, Redfin uses rolling three-month periods. In this tool, a point ending in August covers June through August; the next point covers July through September. Two months overlap. Redfin's period definitions.

Choose Calendar quarters for separate January–March, April–June, July–September and October–December windows. The site selects those exact source periods; it does not manufacture a quarter by averaging three published medians.

Three habits prevent misleading conclusions:

• Compare the same start and end dates across cities.
• Do not add adjacent rolling sales counts: you would count some sales more than once.
• Do not read the “1 year” chart range as an annual median. It displays a year of observations.

Check the source update and retrieval dates too. Changing a chart setting does not fetch today's closings. These are dated, nominal-dollar observations, not current asking prices or inflation-adjusted returns.

5. Read the sample before narrowing the search

The comparison charts withhold price points when the reported sales count is below ten or unknown. A gap does not mean prices or sales were zero. Ten is a display rule, not a guarantee that the remaining homes resemble yours.

Move into the San Mateo guide or Redwood City guide to inspect the next layer of evidence. Keep citywide trends separate from the homes matching your filters: bedroom, bathroom and size selections do not recalculate the citywide Redfin series.

6. Know what public property records can answer

Our public address and reported-price records cover all 20 San Mateo County cities and towns. Coverage and available fields vary. The city charts cover 25 cities, including San Francisco, where this site's individual public sale records have not been added.

You can start with three-bedroom single-family records in San Mateo and Redwood City. Unknown or conflicting bedroom values are excluded by that filter. Bedrooms and bathrooms describe current source records, which may differ from the home when it sold.

Keep reported transfer histories separate from latest-sale snapshots. A snapshot retains a parcel's latest reported sale; selecting an earlier year cannot recover every transaction from that year. San Mateo's published transfer layer exposes document, amount and date fields, but those fields alone do not establish an ordinary market sale. An assessed value is another distinct measure, not an asking price.

Verified interior square footage is unavailable in our current public-record collection. Lot area cannot fill that gap. A blank result means missing coverage or no matching captured records, not proof that no suitable homes sold.

7. Finish with actual comparable homes

On a city guide, choose My sales CSV, then Choose a sold-home CSV to load a file you obtained from your agent or another permitted source. It supports date, home type, bedroom, bathroom, price and interior-size filters. Missing size excludes a row when you apply a size filter; inspect that coverage before trusting the narrower sample.

The file stays in your browser tab and clears when removed or reloaded. It is not uploaded or added to our city statistics. You remain responsible for checking whether its sales are comparable, including condition and location.

Finally, put the homes you are considering into the home decision worksheet. Enter the purchase prices you want to evaluate, then compare ownership costs and unresolved checks. Our guide to Bay Area homeownership costs beyond the mortgage explains what to include in that budget. Keep historical prices as evidence alongside that decision. A useful city comparison helps you ask better questions about a home; it does not supply the offer price.