2026 data report

Average class size in California public schools

Statewide trends and county leaderboards for average class size, sourced directly from CDE SARC. Lower is better.

From CDE SARC, cycles 22-23, 23-24, 24-25. Last refreshed 2026-05-15.

Statewide trend

Median (plum line) and p25–p75 band (mist), all California public schools per cycle.

Best 25 counties — Average class size

  1. 1Trinity5.0
  2. 2Mariposa6.6
  3. 3Mono8.8
  4. 4Inyo9.8
  5. 5Plumas11.7
  6. 6Lassen11.8
  7. 7Tuolumne12.3
  8. 8Mendocino14.5
  9. 9Modoc15.6
  10. 10Humboldt16.9
  11. 11Siskiyou17.0
  12. 12Glenn18.2
  13. 13Shasta19.2
  14. 14Lake19.5
  15. 15Nevada19.6
  16. 16Sutter20.2
  17. 17Madera20.4
  18. 18San Francisco20.6
  19. 19Sonoma21.2
  20. 20Los Angeles21.4
  21. 21Yuba21.5
  22. 22Santa Barbara21.9
  23. 23San Benito22.1
  24. 24Tulare22.1
  25. 25Tehama22.2

Worst 25 counties — Average class size

  1. 1Napa26.8
  2. 2Orange24.7
  3. 3Ventura24.3
  4. 4Riverside24.3
  5. 5Sacramento24.2
  6. 6Imperial24.0
  7. 7Merced24.0
  8. 8Solano23.8
  9. 9Santa Clara23.8
  10. 10San Bernardino23.6
  11. 11Placer23.5
  12. 12Fresno23.3
  13. 13San Joaquin23.2
  14. 14Santa Cruz23.1
  15. 15San Diego22.9
  16. 16San Mateo22.8
  17. 17Kern22.8
  18. 18San Luis Obispo22.8
  19. 19Marin22.7
  20. 20Stanislaus22.6
  21. 21Kings22.5
  22. 22Yolo22.5
  23. 23Monterey22.3
  24. 24Tehama22.2
  25. 25Tulare22.1

How we score this

Every California public school's raw number is mapped to a 0–10 score using the absolute anchor table below — no peer-relative ranking.

Average class size

Lower is better

Column: AVG_SIZE

PercentileRaw valueScore
5th13.1210
50th23.625
95th300

Values between the 5th and 95th percentile are linearly interpolated. Outside that range, scores clamp at 0 or 10.

Read the full methodology →