How School District Ratings Work

A plain-language explanation of our data sources, rating methodology, update schedule, and known limitations.

📊 Primary Data Source

All school district data on this site comes from the NCES Common Core of Data (CCD), the US Department of Education's annual census of public elementary and secondary education. It is the most comprehensive, authoritative, and free public dataset on US school districts.

Data Field	Source	Year
District names & LEAIDs	NCES CCD Directory	2024–2025
Enrollment (students)	NCES CCD Membership	2024–2025
Per-pupil spending	NCES CCD Fiscal	2022–2023 (latest available)
Number of schools	NCES CCD School Universe	2024–2025
Zip-to-district mapping	US Census TIGER/Line + NCES	2024
District boundary maps	US Census TIGER Web Services	Live

⭐ How Ratings Are Calculated

Ratings measure student academic outcomes: the percentage of a district’s students who score proficient or above on state reading and math assessments, as reported to the U.S. Department of Education (EDFacts). We average reading and math proficiency, then percentile-rank each district within its own state and convert that to a 1–10 score — so a rating reflects how a district compares to its in-state peers.

Reading Proficiency

Share of students meeting state standards in reading / English language arts, from the U.S. Dept. of Education EDFacts assessment collection (2021–22 school year for 90% of districts, with a 2017–18 fallback for the rest where the newer file lacks data).

Math Proficiency

Share of students meeting state standards in mathematics, from the same federal EDFacts collection.

State Normalization

Reading and math are averaged, then percentile-ranked against every other district in the same state and mapped to a 1–10 score.

Geographic Matching

Each zip is matched to its district by location — a point-in-polygon lookup against U.S. Census TIGER district boundaries — not by name, so the rating belongs to the district that actually serves the area.

Rating scale: 9–10 = Excellent · 7–8 = Good · 5–6 = Average · 3–4 = Below Average · 1–2 = Poor

“Not rated”: Some districts are shown as Not rated rather than given a number. This happens where the Department of Education does not publish district-level proficiency — typically very small districts whose scores are suppressed for privacy, or large systems (such as New York City) that report at the sub-district level. We would rather show no rating than a guess. Proficiency reflects the most recent complete federal assessment collection (2017–2019); nationwide testing was paused in 2020.

🤖 Machine-Readable Data & API

All district data is available as static JSON — no API key, no rate limits, no authentication required.

# By zip code
GET https://www.schooldistrictfinder.us/api/zip/90210.json

# By NCES LEAID
GET https://www.schooldistrictfinder.us/api/district/0604830.json

# Example response
{
  "zip": "90210",
  "district": "Beverly Hills Unified School District",
  "city": "Beverly Hills",
  "state": "CA",
  "county": "Los Angeles County",
  "rating": 9,
  "students": "3,500",
  "schools": "6",
  "per_pupil": "$21,000/yr",
  "leaid": "0604830"
}

Each zip page also embeds this data inline as <script type="application/json" id="district-data"> for parsers that read HTML. The LEAID field links to the NCES district database and the US Census TIGER school district boundary service.

🌐 District Boundary Maps

Interactive boundary maps on each district page are loaded live from the US Census Bureau TIGER Web Services. The LEAID field in our data is the key that connects to this service.

# Fetch district boundary GeoJSON directly from Census TIGER
# (Unified School Districts = layer 0)
GET https://tigerweb.geo.census.gov/arcgis/rest/services/TIGERweb/School/MapServer/0/query
  ?where=GEOID='0604830'
  &outFields=NAME,GEOID
  &outSR=4326
  &f=geojson

🔄 Update Schedule

District Data

Updated annually when NCES releases new CCD data (typically October–December).

Boundary Maps

Loaded live from Census TIGER — always current.

Per-Pupil Spending

Fiscal data typically lags enrollment data by 1–2 years.

⚠️ Known Limitations

Zip codes are not districts. A zip code can span multiple districts, and a district can span many zip codes. We map each zip to its primary district — the one serving the largest share of the zip's area. Fringe addresses may be in a different district.
Charter and private schools are not included in district assignments. NCES CCD covers public school districts only.
Intra-district school choice is not reflected. Some districts allow open enrollment across schools.
Ratings are relative, not absolute. A 7/10 in one state may not equal a 7/10 in another — scores are percentile-ranked within each state.
Always verify with your local district before making enrollment, housing, or school-choice decisions.

🔗 Primary Sources

NCES Common Core of Data (CCD) — main data source
NCES District Search — look up any district by LEAID
US Census TIGER School District Boundaries
Census SAIPE — School District Estimates