The largest districts with a page here

The 260 districts with a page on this site, ranked by the number of homes inside the boundary, counted from census blocks rather than from enrollment. This is not the country’s league table: a page is earned by having something of its own to say, so the largest district in the United States, New York City Department Of Education at 3,618,620 homes, is not on it. Covering many homes and covering many ZIP Code areas are not the same thing, but on this list they run together more than apart: the rank correlation between the two orders is 0.75, and 7 of the first ten by homes are also in the first ten by ZIP Code areas.

What to do next

Ask the district office to confirm your street address. A district settles that question on its own site: look for a school locator, a find my school tool, or an attendance zone map. Where there is none, ask the office itself.

A ZIP Code is a set of mail delivery routes, not a boundary: 17,865 of the 33,555 ZIP Code areas in the country with homes in them are served by more than one school district, and the line between two of them runs along streets. Only the district can say which side of that line an address is on.

This site links to no district website. None of the federal files it is built from publishes one, and a guessed address is worse than none. It is the district office, not a search engine, that settles an address.

If a house purchase depends on the answer, ask the district itself for written confirmation of that exact address. A listing is not a district record, and neither is this page.

What size does and does not settle

A district on this list covers between 5 and 40 ZIP Code areas: Shelby County reaches the most at 40, Manchester the fewest at 5. Size buys reach, not exclusivity. In 7 of these 60 districts the areas where the district is the only real answer outnumber the areas it shares, which leaves 53 where it shares at least as many areas as it holds alone.

The list leans to the states with the largest unified districts (Arizona (7), Texas (5) and California (4)) — and that is a fact about how those states organize schools rather than about crowding: a county-wide district in the South covers every settlement in its county, while the same population in New England is divided among a dozen town districts, none of which comes near this list. That is why the ranking by homes is a poor guide to where a ZIP Code answer is hard, and why the divided areas have a page of their own.

The homes counted here are homes inside the boundary, taken from census blocks, and not enrollment: a district of 347,237 homes does not have 347,237 pupils, and the two numbers move apart wherever households are older or younger than the country as a whole. The reason to count homes is that a home has a location and a pupil does not — the whole of this site is the question of which district a location falls in, and enrollment figures cannot answer it.

What this cannot tell you

The homes were counted in the 2020 Census and the district lines are the 2026 boundary file. Nothing on this page adjusts one to the other. Where houses have been built or cleared since the count, a share here describes the place as it was counted rather than as it stands today, and in the fastest-growing ZIP Code areas that gap is the largest single source of error on this site.

A share on this page is a share of the homes in the ZIP Code area, not a probability for any particular address. Enrollment is decided by street address, and a district may run magnet, charter or choice programs that ignore the boundary entirely. If a decision depends on the answer, the district office is the only authority; this page shows what the federal boundary files say and when they were published.

A district boundary is not a school attendance zone. This site never says which school an address is assigned to: no current national dataset of attendance zones exists, and the district draws them itself. Nor is anything here endorsed or certified by the Census Bureau; we use their published files, and that is the whole of the relationship.

A ZIP Code is a set of mail delivery routes, not an area. What is mapped here is the Census Bureau's ZIP Code Tabulation Area, the closest published approximation to it. The two are not identical, and a handful of ZIP Codes used only for post office boxes or single buildings have no tabulation area at all.