Castro Valley vs Baywood, San Mateo
Castro Valley carries an effective property tax rate of 1.20% of assessed value and Baywood, San Mateo carries 1.11%, both for fiscal year 2025-26. On one identical reference loan the monthly carrying costs are $9,893 and $9,764 — $129 apart, with Baywood, San Mateo lower. To Oakland City Center at AM peak the fastest published commutes are 28 min by BART from Castro Valley and 45 min by car from Baywood, San Mateo. Every figure is an objective public metric or arithmetic on one, and names its source.
Castro Valley (Alameda County) · Baywood, San Mateo (San Mateo County)
| Metric | Castro Valley | Baywood, San Mateo | Difference |
|---|---|---|---|
| Median $/sqft (SFR) | $650 | $1,400 | −$750 |
| Effective tax rate | 1.20% | 1.11% | +0.097% |
| Monthly cost, reference loan | $9,893 | $9,764 | +$129 |
| FiDi SF (Montgomery St BART) — BART | 45 min | 48 min | −3 min |
| FiDi SF (Montgomery St BART) — Drive | 50 min | 45 min | +5 min |
| Oakland City Center (12th St BART) — BART | 28 min | 62 min | −34 min |
| Oakland City Center (12th St BART) — Drive | 28 min | 45 min | −17 min |
| Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive | 50 min | 30 min | +20 min |
Difference is Castro Valley minus Baywood, San Mateo. Sources are cited on each submarket page.
Put the two side by side and the gap is square footage, not tax: $650 per foot in Castro Valley against $1,400 in San Mateo (Baywood). On the same $1,600,000 purchase the monthly separation is $129, because Castro Valley bills 1.20% and San Mateo (Baywood) 1.11%.
The house at each price
Castro Valley is the Alameda County value play for a buyer who needs both I-580 and I-880. Baywood comps run $1,200-$1,400 per square foot. At $650 and $1,400 per foot respectively, a fixed budget buys about 115% more floor area in Castro Valley.
The monthly, matched
Holding the loan constant — $1,600,000, 20% down, 6.5% on a 30-year fixed, $2,400 of insurance, no HOA — Castro Valley totals $9,893 a month at 1.20% and San Mateo (Baywood) $9,764 at 1.11% — tax lines of $1,603 and $1,473. A few Five Canyons tracts still carry a small CFD, so the Castro Valley bill has to be checked. No Mello-Roos in Baywood. Neither figure includes dues or a district assessment, and both belong on the worksheet before an offer.
The trip each morning
To Sunnyvale / Mountain View (Sunnyvale Caltrain): 50 minutes by driving from Castro Valley, 30 by Caltrain from San Mateo (Baywood) — a 20-minute edge to San Mateo (Baywood), or 3.3 hours across a ten-trip week. To Oakland City Center (12th St BART): 28 minutes by BART from Castro Valley, 45 by driving from San Mateo (Baywood) — a 17-minute edge to Castro Valley, or 2.8 hours across a ten-trip week. Hayward and San Leandro job centers are 10-15 minutes from Castro Valley. San Mateo Caltrain is a 10-minute walk from lower Baywood.
Hazard and insurance
Insurance is priced off mapping, not off price per foot. The Hayward Fault runs through the west side of Castro Valley and is on every disclosure. Baywood is not WUI. Pull the parcel's own mapping — CAL FIRE severity zone, FEMA flood panel, CGS liquefaction zone — and get a written quote before the contingency date.
Choosing between them
Castro Valley fits a four-bedroom-under-$1.2M requirement with a BART option. Baywood fits a walkable-Caltrain requirement with a period house. Write the requirement down before the search: these two answer different ones.
Sources. Rate and payment figures: Alameda County Tax Rates by TRA FY 2025-26; San Mateo County Tax Rate Book FY 2025-26, as composited in build/assets/metrics.json — unverified at tax-rate-area level, so read the bill. Minutes shown are AM-peak and door to door, from data/commute/static.csv. Price per square foot is a trailing median and is not an appraisal. Qualitative detail is the broker's own field observation.
Compare any two submarkets
| Metric | Castro Valley | Baywood, San Mateo |
|---|---|---|
| Median $/sqft (SFR) | $650 | $1,400 |
| Effective tax rate | 1.20% | 1.11% |
| Monthly cost, reference loan | $9,893 | $9,764 |
| Fastest to FiDi SF (Montgomery St BART) | 45 min | 45 min |
| Fastest to Oakland City Center (12th St BART) | 28 min | 45 min |
| Fastest to Sunnyvale / Mountain View (Sunnyvale Caltrain) | 50 min | 30 min |
Same reference loan on both sides; the tax line is the only variable. Commute figures are door-to-door AM-peak estimates. Sources are listed on each submarket page.
Castro Valley detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.042% |
| School district measures | 0.160% |
| Effective rate | 1.20% |
| Mello-Roos / CFD | None recorded |
Source: Alameda County Tax Rates by TRA FY 2025-26 (Alameda County), composited in
build/assets/metrics.json.
Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.
Baywood, San Mateo detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.010% |
| School district measures | 0.095% |
| Effective rate | 1.10% |
| Mello-Roos / CFD | None recorded |
Source: San Mateo County Tax Rate Book FY 2025-26 (San Mateo County), composited in
build/assets/metrics.json.
Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.
Castro Valley vs Baywood, San Mateo: questions and answers
- Which has the lower effective property tax rate, Castro Valley or Baywood, San Mateo?
- Baywood, San Mateo, at 1.11% of assessed value against 1.20% for fiscal year 2025-26 — a gap of 0.090%. Rates are composited from county tax rate books; each parcel bill governs.
- How much do monthly carrying costs differ between Castro Valley and Baywood, San Mateo?
- $129 per month on the identical reference loan: Castro Valley $9,893, Baywood, San Mateo $9,764. Baywood, San Mateo is lower. Principal and interest are held constant, so the difference is the tax line. Arithmetic only.
- Which has the shorter commute to Oakland City Center, Castro Valley or Baywood, San Mateo?
- Castro Valley. Castro Valley is 28 min by BART; Baywood, San Mateo is 45 min by car. Door-to-door, AM peak. Source: data/commute/static.csv.
- What is the price per square foot difference between Castro Valley and Baywood, San Mateo?
- $750 per square foot: Castro Valley $650, Baywood, San Mateo $1,400. Single-family medians, trailing twelve months. A median is not a valuation of any specific property.