Foster City vs Rockridge, Oakland
Foster City carries an effective property tax rate of 1.10% of assessed value and Rockridge, Oakland carries 1.36%, both for fiscal year 2025-26. On one identical reference loan the monthly carrying costs are $9,760 and $10,104 — $344 apart, with Foster City lower. To Oakland City Center at AM peak the fastest published commutes are 40 min by car from Foster City and 12 min by BART from Rockridge, Oakland. Every figure is an objective public metric or arithmetic on one, and names its source.
Foster City (San Mateo County) · Rockridge, Oakland (Alameda County)
| Metric | Foster City | Rockridge, Oakland | Difference |
|---|---|---|---|
| Median $/sqft (SFR) | $1,000 | $1,000 | $0 |
| Effective tax rate | 1.10% | 1.36% | −0.258% |
| Monthly cost, reference loan | $9,760 | $10,104 | −$344 |
| FiDi SF (Montgomery St BART) — BART | 58 min | 25 min | +33 min |
| FiDi SF (Montgomery St BART) — Drive | 45 min | 35 min | +10 min |
| Oakland City Center (12th St BART) — BART | 70 min | 12 min | +58 min |
| Oakland City Center (12th St BART) — Drive | 40 min | 15 min | +25 min |
| Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive | 30 min | 70 min | −40 min |
Difference is Foster City minus Rockridge, Oakland. Sources are cited on each submarket page.
40 minutes each way to Sunnyvale / Mountain View (Sunnyvale Caltrain) is what actually separates Foster City from Rockridge; Foster City holds that side. Both are billed within 0.26% of each other, 1.10% to 1.36%.
Square footage per dollar
$1.4M in Rockridge is a 1910s-20s Craftsman bungalow, 1,400-1,700 sq ft, on a 4,000-5,000 sq ft lot. Against that, waterfront Foster City homes on the lagoon or bay start at $2M. The median foot costs $1,000 in Foster City against $1,000 in Rockridge; on a 2,000 sq ft house that is $0 of purchase price.
Carrying $1,600,000 in each
Against an identical $1,600,000 note at 6.5% with 20% down and $2,400 a year of coverage, Foster City totals $9,760 a month at 1.10% and Rockridge $10,104 at 1.36% — tax lines of $1,469 and $1,813. No Mello-Roos on Foster City resale stock; Pilgrim-Triton condos carry $600-$900 a month. No Mello-Roos and no HOA on the Rockridge bungalows. Neither figure includes dues or a district assessment, and both belong on the worksheet before an offer.
Commute, measured
To Sunnyvale / Mountain View (Sunnyvale Caltrain): 30 minutes by driving from Foster City, 70 by driving from Rockridge — a 40-minute edge to Foster City, or 6.7 hours across a ten-trip week. To Oakland City Center (12th St BART): 40 minutes by driving from Foster City, 12 by BART from Rockridge — a 28-minute edge to Rockridge, or 4.7 hours across a ten-trip week. Driving 101 from Foster City to SoMa is 25 minutes at 6 a.m. and 45-60 at 8. Door to door from the Rockridge bungalows to FiDi is 25-35 minutes, the shortest rail commute in this set.
Fire, flood and the premium
Foster City is not WUI. Lower Rockridge below Broadway is not WUI. Run the address through CAL FIRE's severity-zone viewer, the FEMA Flood Map Service Center and the CGS seismic hazard maps, and treat the premium quote as a contingency item.
The housing need each answers
Foster City fits a flat, bike-scale layout requirement. Rockridge suits a buyer who prefers a 1920s house to new construction. The decision is which requirement is load-bearing, because neither submarket satisfies both lists.
Sources. Tax figures come from San Mateo County Tax Rate Book FY 2025-26; Alameda County Tax Rates by TRA FY 2025-26, composited in build/assets/metrics.json. They are county-level and not yet verified at the TRA, so the parcel's bill governs. Travel times are AM-peak door-to-door estimates from data/commute/static.csv. Median price per foot is a trailing figure, not a valuation, and the local detail comes from the broker's own transactions.
Compare any two submarkets
| Metric | Foster City | Rockridge, Oakland |
|---|---|---|
| Median $/sqft (SFR) | $1,000 | $1,000 |
| Effective tax rate | 1.10% | 1.36% |
| Monthly cost, reference loan | $9,760 | $10,104 |
| Fastest to FiDi SF (Montgomery St BART) | 45 min | 25 min |
| Fastest to Oakland City Center (12th St BART) | 40 min | 12 min |
| Fastest to Sunnyvale / Mountain View (Sunnyvale Caltrain) | 30 min | 70 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.
Foster City detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.010% |
| School district measures | 0.092% |
| 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.
Rockridge, Oakland detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.152% |
| School district measures | 0.208% |
| Effective rate | 1.36% |
| 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.
Foster City vs Rockridge, Oakland: questions and answers
- Which has the lower effective property tax rate, Foster City or Rockridge, Oakland?
- Foster City, at 1.10% of assessed value against 1.36% for fiscal year 2025-26 — a gap of 0.260%. Rates are composited from county tax rate books; each parcel bill governs.
- How much do monthly carrying costs differ between Foster City and Rockridge, Oakland?
- $344 per month on the identical reference loan: Foster City $9,760, Rockridge, Oakland $10,104. Foster City 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, Foster City or Rockridge, Oakland?
- Rockridge, Oakland. Foster City is 40 min by car; Rockridge, Oakland is 12 min by BART. Door-to-door, AM peak. Source: data/commute/static.csv.
- What is the price per square foot difference between Foster City and Rockridge, Oakland?
- $0 per square foot: Foster City $1,000, Rockridge, Oakland $1,000. Single-family medians, trailing twelve months. A median is not a valuation of any specific property.