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Data study

Where the Bay Area’s Young Kids Live: Children Under 10 by City

The nine-county Bay Area had an estimated 787,073 children under 10 in 2020-2024, 9.7% fewer than in 2015-2019 (871,660), according to the Census Bureau’s American Community Survey. San Jose alone had 104,005, down 17.3%; 33 of the region’s 101 cities and towns had a clear drop and 6 a clear rise.

By Bay Area Kids Rentals · Published November 12, 2026 · Download the data (CSV)

Key numbers

787,073
children under 10 in the nine Bay Area counties, 2020-2024 (margin of error ±3,768).U.S. Census Bureau, ACS 5-year 2020-2024, table B01001
−9.7%
against 871,660 in 2015-2019. Per 1,000 households, from 319 to 281 children under 10.U.S. Census Bureau, ACS 5-year, B01001 and B11001
104,005
children under 10 in San Jose, the most of any Bay Area city, down 17.3% from 125,763.U.S. Census Bureau, ACS 5-year, 2015-2019 and 2020-2024
33 of 101
cities and towns had a clear drop in children under 10; 6 had a clear rise, 59 no clear change and 3 were too close to call.U.S. Census Bureau, ACS 5-year, 90% margins of error
32.9%
of the region’s children under 10 lived in five cities: San Jose, San Francisco, Oakland, Fremont and Sunnyvale.U.S. Census Bureau, ACS 5-year 2020-2024

The data

Children under 10 by city

Children under 10 are the Census Bureau’s “under 5 years” and “5 to 9 years”, boys and girls together. The chart shows the 15 cities with the most; the table lists all 101 cities and towns in the nine counties, in order of the number of children, with the margin of error and the change since 2015-2019.

Children under 10, 2020-2024: the 15 cities with the most
San Jose104,005
San Francisco63,821
Oakland45,791
Fremont27,381
Sunnyvale17,922
Santa Rosa17,426
Hayward16,571
Fairfield15,627
Concord15,069
Antioch13,918
Santa Clara13,378
Vallejo13,142
Vacaville12,704
Richmond12,047
Livermore11,103

Estimates, U.S. Census Bureau, ACS 5-year 2020-2024, table B01001. Margins of error are in the table below.

All 101 Bay Area cities and towns, by number of children under 10, 2020-2024. “Clear change” means the change is larger than its 90% margin of error; “too close to call” means within 5% of that line. Source: U.S. Census Bureau, ACS 5-year, tables B01001 and B11001.
City or townCountyUnder 10, 2020-2024±Under 55 to 9Under 10, 2015-2019ChangeClear change?Per 1,000 households
San JoseSanta Clara104,0052,06050,01253,993125,763−17.3%Down317
San FranciscoSan Francisco63,8211,09634,14629,67570,875−10.0%Down175
OaklandAlameda45,7911,64924,04021,75148,786−6.1%Down259
FremontAlameda27,3811,22212,48214,89930,681−10.8%Down351
SunnyvaleSanta Clara17,9221,0959,9777,94520,481−12.5%Down297
Santa RosaSonoma17,4261,0018,4648,96221,249−18.0%Down255
HaywardAlameda16,5711,0358,5967,97518,943−12.5%Down334
FairfieldSolano15,6279827,8057,82216,435−4.9%No clear change403
ConcordContra Costa15,0691,1408,2306,83916,216−7.1%No clear change326
AntiochContra Costa13,9181,0456,8497,06913,766+1.1%No clear change372
Santa ClaraSanta Clara13,3789766,9166,46215,854−15.6%Down267
VallejoSolano13,1428946,8326,31013,994−6.1%No clear change293
VacavilleSolano12,7048855,3417,36312,218+4.0%No clear change370
RichmondContra Costa12,0471,1045,5536,49414,325−15.9%Down295
LivermoreAlameda11,1038734,8506,25311,701−5.1%No clear change359
San MateoSan Mateo11,0848136,0994,98513,590−18.4%Down278
DublinAlameda10,0917294,3015,79010,003+0.9%No clear change418
San RamonContra Costa9,8777624,2285,64910,072−1.9%No clear change328
AlamedaAlameda9,6478194,7264,9219,259+4.2%No clear change322
Mountain ViewSanta Clara8,9448984,8354,10910,083−11.3%Too close to call250
Redwood CitySan Mateo8,9037394,1744,72910,658−16.5%Down297
MilpitasSanta Clara8,7587203,9854,77310,629−17.6%Down349
PittsburgContra Costa8,3127844,5823,73010,526−21.0%Down350
BerkeleyAlameda8,3106213,9914,3198,209+1.2%No clear change176
BrentwoodContra Costa8,1178533,4124,7057,394+9.8%No clear change381
San LeandroAlameda7,8987173,7834,1159,554−17.3%Down259
GilroySanta Clara7,8557943,7404,1158,286−5.2%No clear change450
PleasantonAlameda7,8257343,2264,5998,878−11.9%Down281
NapaNapa7,6814653,9243,7579,172−16.3%Down256
Daly CitySan Mateo7,3586783,5413,8178,985−18.1%Down228
Palo AltoSanta Clara7,0396623,2213,8187,091−0.7%No clear change271
Walnut CreekContra Costa6,4446543,0163,4286,765−4.7%No clear change195
Morgan HillSanta Clara6,2637253,5332,7305,888+6.4%No clear change421
San RafaelMarin6,0356672,8893,1467,120−15.2%Down263
South San FranciscoSan Mateo5,9285922,7253,2036,474−8.4%No clear change271
CupertinoSanta Clara5,8455842,2203,6256,913−15.4%Down278
Union CityAlameda5,8115822,9672,8447,940−26.8%Down274
PetalumaSonoma5,7775202,5473,2306,500−11.1%Too close to call238
NovatoMarin5,7216602,3433,3785,232+9.3%No clear change285
OakleyContra Costa5,6918043,0792,6126,441−11.6%No clear change416
Rohnert ParkSonoma5,3367432,6032,7334,922+8.4%No clear change311
Danville (town)Contra Costa5,2355742,2103,0255,466−4.2%No clear change337
NewarkAlameda5,2275053,0282,1995,340−2.1%No clear change343
CampbellSanta Clara5,2216113,0092,2125,260−0.7%No clear change309
MartinezContra Costa4,6166172,4172,1993,995+15.5%No clear change314
Foster CitySan Mateo4,0694802,1171,9524,337−6.2%No clear change313
Menlo ParkSan Mateo3,9714571,9172,0545,022−20.9%Down335
San PabloContra Costa3,8576091,7222,1354,008−3.8%No clear change396
Los Gatos (town)Santa Clara3,8564721,4652,3912,774+39.0%Up303
San BrunoSan Mateo3,8195071,9421,8774,465−14.5%No clear change251
San CarlosSan Mateo3,7293921,7102,0194,298−13.2%Down339
Pleasant HillContra Costa3,5634551,6121,9514,000−10.9%No clear change269
BurlingameSan Mateo3,4634431,7291,7343,912−11.5%No clear change282
Suisun CitySolano3,4455011,6241,8213,769−8.6%No clear change358
Los AltosSanta Clara3,3524051,3092,0433,636−7.8%No clear change309
PacificaSan Mateo3,2364151,6231,6134,233−23.6%Down233
BelmontSan Mateo3,1614611,4481,7133,148+0.4%No clear change301
East Palo AltoSan Mateo3,0404761,6961,3444,943−38.5%Down368
LafayetteContra Costa3,0374541,1781,8592,985+1.7%No clear change316
BeniciaSolano2,9834601,4651,5182,747+8.6%No clear change270
Windsor (town)Sonoma2,6993981,0641,6353,352−19.5%Down294
DixonSolano2,6175531,4041,2132,543+2.9%No clear change384
OrindaContra Costa2,5953821,1531,4421,805+43.8%Up357
HerculesContra Costa2,5144311,0021,5122,422+3.8%No clear change269
El CerritoContra Costa2,5102791,2991,2112,711−7.4%No clear change232
American CanyonNapa2,4203631,0871,3332,400+0.8%No clear change404
MillbraeSan Mateo2,3863271,3121,0742,430−1.8%No clear change294
SaratogaSanta Clara2,2633466901,5732,350−3.7%No clear change210
AlbanyAlameda2,1912551,1421,0492,762−20.7%Down287
Moraga (town)Contra Costa1,9353199789571,385+39.7%Up349
PiedmontAlameda1,7873878749131,115+60.3%Up462
San Anselmo (town)Marin1,6873406791,0081,282+31.6%Too close to call323
Half Moon BaySan Mateo1,4712747926791,183+24.3%No clear change362
PinoleContra Costa1,4532716827711,856−21.7%Down221
Hillsborough (town)San Mateo1,2632823678961,299−2.8%No clear change350
Corte Madera (town)Marin1,2283387075211,251−1.8%No clear change304
Mill ValleyMarin1,1392303647751,546−26.3%Down200
LarkspurMarin1,070226563507949+12.8%No clear change178
ClaytonContra Costa1,0433143397041,101−5.3%No clear change262
HealdsburgSonoma1,0292685205091,028+0.1%No clear change221
Tiburon (town)Marin803196343460839−4.3%No clear change229
CotatiSonoma7722234253471,067−27.6%No clear change242
CloverdaleSonoma7712341935781,151−33.0%Down223
Los Altos Hills (town)Santa Clara668196307361615+8.6%No clear change221
EmeryvilleAlameda660258528132699−5.6%No clear change84
BrisbaneSan Mateo568176221347668−15.0%No clear change297
Rio VistaSolano568237230338235+141.7%Up113
SebastopolSonoma563160319244654−13.9%No clear change170
SonomaSonoma553165242311769−28.1%No clear change105
Fairfax (town)Marin547188393154605−9.6%No clear change168
St. HelenaNapa505150225280755−33.1%Down216
Portola Valley (town)San Mateo495193252243399+24.1%No clear change280
Woodside (town)San Mateo487111273214640−23.9%No clear change273
Ross (town)Marin485168160325272+78.3%Up579
Atherton (town)San Mateo352108147205619−43.1%Down158
SausalitoMarin34311026974469−26.9%No clear change86
Monte SerenoSanta Clara25788132125405−36.5%Down200
BelvedereMarin23691100136167+41.3%No clear change266
Colma (town)San Mateo1978068129110+79.1%No clear change418
CalistogaNapa19612583113604−67.5%Down98
YountvilleNapa107172406781+32.1%No clear change72

All 101 Bay Area cities and towns, by number of children under 10, 2020-2024. “Clear change” means the change is larger than its 90% margin of error; “too close to call” means within 5% of that line. Source: U.S. Census Bureau, ACS 5-year, tables B01001 and B11001.

Download the full table (CSV), free to reuse under CC BY 4.0 with credit to Bay Area Kids Rentals.

By county

Children under 10 by county

8 of the 9 counties had a clear drop. The largest were in San Mateo (−14.3%), Napa (−14.0%) and Santa Clara (−13.3%).

Nine Bay Area counties, U.S. Census Bureau, ACS 5-year 2015-2019 and 2020-2024, table B01001.
CountyUnder 10, 2020-2024±Under 10, 2015-2019ChangeClear change?Per 1,000 households
Santa Clara County202,8962,070234,002−13.3%Down308
Alameda County175,8861,375192,129−8.5%Down294
Contra Costa County130,5711,647137,899−5.3%Down315
San Mateo County76,2021,17488,892−14.3%Down288
San Francisco County63,8211,09670,875−10.0%Down175
Solano County52,9551,00053,992−1.9%No clear change336
Sonoma County47,3791,01952,867−10.4%Down248
Marin County24,84269926,440−6.0%Down241
Napa County12,52145314,564−14.0%Down252
Nine-county Bay Area787,0733,768871,660−9.7%Down281

Nine Bay Area counties, U.S. Census Bureau, ACS 5-year 2015-2019 and 2020-2024, table B01001.

Where it rose

The 6 places with a clear rise

Children under 10 rose clearly in Los Gatos (2,774 to 3,856), Orinda (1,805 to 2,595), Moraga (1,385 to 1,935), Piedmont (1,115 to 1,787), Rio Vista (235 to 568) and Ross (272 to 485). All are smaller places (under 4,000 children under 10 each), where a gain of 213 to 1,082 children is a large percentage change; their margins of error are in the table and the CSV.

For parents

What this means for parents

  • Find your city in the table, with its margin of error. For towns with a few thousand children or fewer, the margins are wide, so a change marked “no clear change” or “too close to call” may be sampling noise.
  • Big-city parks are shared by many families. San Jose, San Francisco and Oakland together had 213,617 children under 10. Where so many families share the parks, reserve a picnic site early: our park bounce house rules study shows where each city allows a bounce house and what it asks for.
  • Fewer young children than five years earlier, but not everywhere. The region had 9.7% fewer children under 10, yet 62 of the 101 cities and towns had no clear change or were too close to call, and 6 had more.
  • These are counts, not a ranking. The table is ordered by the number of children; it does not say which city is better for families.

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How we did it

Method, sources and limits

We used the Census Bureau’s American Community Survey 5-year estimates for two periods that do not overlap, 2015-2019 and 2020-2024: table B01001 (Sex by Age) for children under 5 and 5 to 9, boys and girls added together, and table B11001 for households. The Bay Area is the nine counties around the Bay (Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano and Sonoma); the 101 cities and towns are every incorporated place in those counties, using the Census Bureau’s 2024 place-to-county list.

Margins of error are at 90%. For a sum we used the Bureau’s approximation (the square root of the sum of squared margins). A change counts as clear when it is larger than the combined margin of the two periods, the Bureau’s own test. Because the margins of sums are approximations, a change within 5% of that line is shown as “too close to call” (Mountain View, Petaluma and San Anselmo).

Independent check: a separate script downloaded the same estimates from the Census Bureau’s subject tables instead (S0101 Age and Sex and S1101 Households, a different endpoint), recomputed all 637 city, county and regional figures with its own code, and matched every one exactly, including the counts of clear rises and drops using S0101’s own margins.

Sources

Limits

  • ACS figures are estimates from a survey, not a count. Each comes with a margin of error, which is large for small towns.
  • 5-year estimates describe a whole five-year period, not a single year: 2020-2024 includes the pandemic years.
  • Each period uses its own city boundaries, so an annexation between the two periods would show up as a change.
  • City figures cover the incorporated city or town only, not unincorporated areas such as Castro Valley or Alamo, which are in the county figures.
  • This is where children live, not where parties happen or how many families book anything.

Free to use

Cite this study

Journalists, schools and parents are welcome to use these figures and the data, with credit to Bay Area Kids Rentals and a link to this page.

Bay Area Kids Rentals. (2026, November 12). Where the Bay Area’s Young Kids Live: Children Under 10 by City. https://www.bayareakidsrentals.com/research/bay-area-kids-by-city/

Data: bay-area-kids-by-city.csv (111 rows), licensed CC BY 4.0. Questions about the data: Hello@bayareakidsrentals.com.

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