What data actually matters
Parents move for schools. The problem is most people compare districts using whichever aggregator (GreatSchools, Niche) their realtor sends. These lean heavily on test scores, which correlate more with median home price than with actual teaching quality. A better comparison pulls 5–6 independent signals: proficiency rates, graduation rate, AP/IB participation, student-teacher ratio, per-pupil spending, and home price.
The five data points
- Proficiency rate (% at or above grade level): from state DOE assessments. Strongest single signal of academic rigor.
- 4-year graduation rate: from NCES. Hidden strongest signal of K-12 system health.
- AP/IB participation rate: Equity of Excellence Index (College Board). Proxy for peer academic culture.
- Student-teacher ratio: 12–17:1 is the high-performing band. Above 22:1 correlates with 0.2–0.3 SD score declines.
- Per-pupil spending: above $14K, diminishing returns on outcomes. Below $10K, spending correlates strongly with outcomes.
Per-pupil spending — the ceiling
Research from CALDER and NBER: above ~$14K per pupil, additional spending produces small gains. Below $10K, each $1K more per pupil correlates with ~0.05–0.1 SD on standardized assessments. Teacher quality mediates more than raw dollars — a district spending $16K with 25:1 ratios underperforms a district spending $13K with 15:1 ratios.
AP/IB participation — the peer effect
Districts where 50%+ of HS students take at least one AP exam have 20–30% higher 4-year college enrollment rates than districts at 25%. This isn’t causation — it’s a proxy for peer academic culture. Your kid’s peers matter for 4 years of daily hours.
Home price premium — is it worth it?
Zillow + NBER studies: each 10-percentile-point increase in school quality adds ~10–15% to home value. A top-10% district vs. median district = ~75–90% home price premium. The math often works out if you can afford it without stretching past 30% DTI. It doesn’t work if you’re at 45% DTI for a top district — financial stress eats away at the benefits of “better schools.”
The composite score
The tool weights proficiency 30%, graduation rate 20%, AP/IB 20%, student-teacher ratio 20% (inverted), per-pupil spending 10%. A district at 75/95/50/14/$17K scores ~38 points on the normalized composite. A district at 50/82/20/22/$11K scores ~20. Run both to see the gap size.
What the composite doesn’t capture
- Special education quality (highly variable within districts).
- Commute time for your specific home.
- Elementary-specific vs high-school-specific quality (many districts have strong elementary + weaker HS, or vice versa).
- Extracurricular strength (music, arts, sports).
- Cultural fit (urban vs suburban, demographic match for your kid).
Pull the composite for quantitative shortlisting, then visit schools in person before committing. District websites, open houses, and PTA meetings tell you far more than score tables.
Data sources
Pull real district data from: NCES (nces.ed.gov), your state DOE (varies by state), College Board’s AP District Honor Roll, and the Common Core of Data. Avoid relying only on GreatSchools or Niche — their ratings fold in parent reviews that skew toward affluent districts regardless of outcome.
Related tools
For college-level cost comparison, see college cost compare. For AP vs IB vs DE decision, see AP vs IB vs DE recommender. For pre-K–12 savings, see 529 plan growth.