Methodology
How we collect, process, and present education data for every US county.
Current vintage: NCES 2022-23 public school data and FY 2022 school-finance data. Last reviewed by Evan Brooks, Data Editor, on May 14, 2026.
Data Sources
SchoolsByCounty draws on two primary federal data sources, both freely available to the public:
National Center for Education Statistics (NCES)
The NCES Common Core of Data (CCD) provides school-level and district-level data for every public school in the United States. We use the following datasets:
- School District Finance Survey (F-33) — per-pupil expenditure by district
- Public School Universe — enrollment counts, school type, grade span
- Local Education Agency Universe — district-level demographics and finance
- Adjusted Cohort Graduation Rate (ACGR) — four-year graduation rates
Source: nces.ed.gov/ccd
U.S. Census Bureau — American Community Survey (ACS)
The ACS 5-Year Estimates (2019-2023) are used as contextual background for some ByCounty education analysis. Current county school score and school-list pages rely on NCES records; ACS-derived attainment metrics are not displayed until county coverage is complete.
Source: data.census.gov
Source Inventory
The production dataset is assembled from these federal source files. All source pulls are performed at build time; the public site serves static county and school pages.
| Source | Dataset Year | Pulled | Fields Used |
|---|---|---|---|
| NCES Common Core of Data Public School Universe | 2022-23 | March 3, 2026 | School name, NCES ID, enrollment, grade span, level, type, district, county FIPS |
| NCES Common Core of Data LEA Universe | 2022-23 | March 3, 2026 | District identifiers, district names, enrollment, county relationships |
| NCES School District Finance Survey (F-33) | FY 2022 | March 3, 2026 | Current operating spending and fall enrollment for per-pupil expenditure |
| NCES Adjusted Cohort Graduation Rate (ACGR) | 2022-23 | March 3, 2026 | Four-year public high school graduation rate where available |
Key Metrics
Each county page presents the following education metrics:
| Metric | Source | Description |
|---|---|---|
| Per-Pupil Expenditure | NCES F-33 | Current operating spending per fall enrollment, including instruction, support services, administration, transportation, and operations. It excludes capital outlays and debt service in the SchoolsByCounty methodology. |
| Graduation Rate | NCES ACGR | Four-year adjusted cohort graduation rate for public high schools |
| School and District Counts | NCES CCD | Public school records, grade ranges, district affiliation, enrollment, and school type |
| School Score | Composite | 0-100 percentile-rank score based on available NCES graduation and finance signals (see Scoring section) |
School Score Calculation
Each county receives a School Score from 0 to 100 using percentile-rank methodology. The process works as follows:
- Data aggregation: Individual school and district data is aggregated to the county level. Per-pupil expenditure is enrollment-weighted across districts. Graduation rates are averaged across high school districts in the county.
- Percentile position: Each county is compared against all 3,144 US counties on each metric. The percentile position determines the score: a county at the 75th percentile for graduation rate scores 75 on that dimension.
- Composite scoring: The available graduation-rate and per-pupil expenditure percentiles are averaged with equal weight. If only one of the two signals is available for a county, the School Score uses that available percentile.
- Scale: The final score remains on the 0-100 percentile scale. Higher values indicate stronger measured public-school outcomes and funding signals relative to other counties in the dataset.
Counties with incomplete data, such as missing graduation rate or expenditure data, receive adjusted scores based on available metrics. These counties are flagged on their individual pages.
Data Freshness and Update Schedule
Government education data follows an annual release cycle. Our current data reflects:
- NCES data: NCES 2022-23 public school data and FY 2022 school-finance data
- Contextual Census data: ACS-derived context is only displayed when county coverage is complete enough for publication.
We update our dataset within 30 days of new NCES or Census data releases, typically once per year. The “Data vintage” label on each county page indicates which release is currently reflected.
AI-Generated Content Disclosure
SchoolsByCounty uses artificial intelligence to generate narrative descriptions on selected state and county pages. These narratives are produced by the Claude AI model (Anthropic) using structured government data as input. The AI does not fabricate data points — all statistics referenced in narratives come directly from the underlying NCES and Census datasets.
Specifically, AI-generated content appears in:
- State-level education narrative summaries
- County comparison text on state pages
- County education overview and FAQ text where reviewed narrative data exists
- Contextual descriptions of education trends
All data tables, charts, scores, and ordered comparison tables are computed directly from government source data without AI involvement. Human editors review AI-generated narratives for accuracy before publication, and legacy county narrative slides with home-search or school-recommendation language are filtered out before rendering.
Limitations
- NCES data covers public schools only. Private school enrollment and performance are not included in county scores.
- Per-pupil expenditure reflects current operating spending and excludes capital outlays and debt service. Transportation and operations can still vary widely by geography.
- Graduation rates are adjusted cohort rates for public high schools. Alternative education programs and GED completion are not counted.
- County boundaries do not always align with school district boundaries. Where districts span multiple counties, data is apportioned by enrollment share.
- Education quality is multidimensional. The School Score captures measurable outcomes and inputs but cannot reflect teacher quality, curriculum rigor, extracurricular offerings, or school culture.
Questions or Corrections
If you believe any data on this site is inaccurate or have questions about our methodology, please contact us. We take data accuracy seriously and will investigate all reported discrepancies.