P.S. 321 William Penn (15K321) is a public school in District 15, Park Slope-Gowanus, Brooklyn, serving grades pre-K, K–5. In 2026, 83% of tested students were proficient in reading and 90% were proficient in math (NYC DOE). Enrollment was 1332 students in 2025–26 (NYC DOE). The average K–5 class size was 22.2 students in 2025–26 (NYC DOE).
Visit school websiteThe one thing to remember
2026 reading proficiency is 83%, higher than most elementary schools in the district and citywide; down 6 points from 2025.
Also worth knowing: Average class size (2025–26) is 22.2, larger than most elementary schools in the district and citywide.
98%
of parents trust the principal
98%
trust their child's teachers
96%
satisfied with the education overall
NYC School Survey 2026. 57% of families answered.
Students here gain more than at most schools serving similar students
Impact score: 0.61 · 79th percentile
The DOE compares results with those of students with similar starting points and backgrounds.
View this school's official NYC DOE School Quality SnapshotReading
83%
students scored at Level 3 or 4
594 students tested
126 students tested
468 students tested
Mathematics
90%
students scored at Level 3 or 4
597 students tested
127 students tested
470 students tested
Excludes charter schools. Weighted by students tested.
New York changed its grades 3–8 tests in 2023. Compare years from 2023 onward with each other, not with earlier years.
Citywide reading scores fell sharply in 2026; NYC Public Schools is reviewing the results. Source: NYC Public Schools
| Year | Reading | Math |
|---|---|---|
| 2018 | 85% | 87% |
| 2019 | 83% | 87% |
| 2022 | 79% | 82% |
| 2023 | 85% | 88% |
| 2024 | 84% | 91% |
| 2025 | 89% | 90% |
| 2026 | 83% | 90% |
Proficiency means scoring at Level 3 or above. Test scores are one measure of a school, not the whole experience.
Economic need index: 9%0.6 mi away
Economic need index: 6%
Economic need index: 24%0.8 mi away
Economic need index: 16%0.3 mi away
Economic need index: 19%0.5 mi away
Economic need index: 41%0.9 mi away
Economic need index: 43%0.9 mi away
Economic need index: 41%0.9 mi away
Economic need index: 75%0.7 mi away
Economic need index: 9%0.6 mi away
Economic need index: 16%0.3 mi away
Economic need index: 6%
Economic need index: 24%0.8 mi away
Economic need index: 19%0.5 mi away
Economic need index: 41%0.9 mi away
Economic need index: 41%0.9 mi away
Economic need index: 43%0.9 mi away
Economic need index: 75%0.7 mi away
| Measure | P.S. 321 William Penn | P.S. 039 Henry Bristow |
|---|---|---|
| 2026 reading proficient | 83% (-6 points vs 2025) | 78% (-14 points vs 2025) |
| 2026 math proficient | 90% (-1 points vs 2025) | 90% (-5 points vs 2025) |
| Average K–5 class size (2025–26) | 22.2 | 20.8 |
| Enrollment (2025–26) | 1332 | 373 |
| Student–teacher ratio (2025–26) | 13.8 | 12.7 |
| Family satisfaction (2026) | 96% | 94% |
| Principal trust (2026) | 98% | 97% |
| Teacher trust (2026) | 98% | 96% |
| Leadership (2026) | 97% | 97% |
| Distance between schools | 0.3 mi | |
P.S. 321 William Penn has higher reading proficiency than P.S. 039 Henry Bristow (83% vs 78%).
Enrollment
1332 students
pre-K, K–5 · up 96 over five years
NYC DOE · 2025–26
Class size
22.2
children in the average K–5 class; about 13.8 students per teacher (2025–26)
NYC DOE · 2025–26
English learners
1%
was 1% in 2024–25
NYC DOE · 2025–26
Economic need
6% of students live in poverty (2025–26)
Economic need index: 6% — the measure we use to compare similar schools.
NYC DOE · 2025–26
Special education
19%
of students here are in special education
NYC DOE · 2025–26
Student body: 65% White, 10% Hispanic, 9% Asian, 2% Black, 13% multiracial, 51% female, 49% male.
Economic need index: 6% — the measure we use to compare similar schools. It combines measures of students’ economic circumstances; it is not a measure of school quality.
NYC DOE · 2026 survey
NYC DOE · 2024–25
Admissions for NYC public schools go through MySchools. Check the attendance zone shown above; zones can change and do not guarantee a seat.
180 7 AVENUE
Source: NYC DOE / NYSED, 2026 · School information · View this school's official NYC DOE School Quality Snapshot
Admissions for NYC public schools go through MySchools.