Hinsdale Township High School District 86

It never has a ZIP Code to itself

At 1,094 homes to the square mile this is city territory, and district lines in a city follow streets. Hinsdale Township High School District 86 covers 28 square miles in all — small enough that a single ZIP Code area can hold most of it, and several ZIP Codes can cut across it.

• Homes inside the boundary30,954
• Residents76,433
• ZIP Code areas it reaches9
• Where it is the only district0
• Where it shares with another district7
• Where it holds under half a percent2
• Land area28 square miles
• Homes per square mile1,094

The ZIP Code areas it reaches

The spread is the thing to notice. In 60521 this district holds 100% of the homes; in 60439 it holds no homes at all. Same district, opposite answers, and a lookup that names it without the share tells the second household the same thing as the first.

• ZIP Code 60521 · Hinsdale, Illinois100% of the homes
• ZIP Code 60514 · Clarendon Hills, Illinois93% of the homes
• ZIP Code 60527 · Burr Ridge, Illinois88% of the homes
• ZIP Code 60561 · Darien, Illinois64% of the homes
• ZIP Code 60523 · Oak Brook, Illinois41% of the homes
• ZIP Code 60559 · Westmont, Illinois10% of the homes
• ZIP Code 60558 · Western Springs, Illinois1.2% of the homes
• ZIP Code 60516 · Downers Grove, Illinois21 homes, under half a percent
• ZIP Code 60439 · Lemont, Illinoisno homes at all

The areas it leads without holding most of the homes

Hinsdale Township High School District 86 is the largest district in 5 ZIP Code areas. Answer with its name alone and the answer misses 8,188 of the 37,933 homes those areas hold — though in 1 of them it holds every home there is. The count is homes, not addresses, and it is the number no lookup prints.

Hinsdale Township High School District 86 holds 6,247 of the 9,798 homes in ZIP Code 60561 · Darien, Illinois, so its name is right for most of the area and wrong for the rest: 3,551 homes with Community High School District 99 and Lemont Township High School District 210.

Hinsdale Township High School District 86 is the largest name in ZIP Code 60523 · Oak Brook, Illinois and still holds a minority of it: 1,980 of 4,781 homes. The other 2,801 homes are with Community High School District 99, DuPage High School District 88, Westmont Community Unit School District 201 and 1 more district. This is the shape that makes a one-name answer worst — the name is right for fewer homes than it is wrong for.

In ZIP Code 60527 · Burr Ridge, Illinois the split runs 11,229 to 1,527 and the larger part is Hinsdale Township High School District 86's: the rest is 1,512 homes with Lyons Township High School District 204 and 15 homes in a district too small to name here.

ZIP Code 60514 · Clarendon Hills, Illinois is a two-district area: 3,817 of its 4,126 homes are inside Hinsdale Township High School District 86, and the other 309 homes are with Westmont Community Unit School District 201. Which one an address belongs to is settled by the street, not by the five digits.

In ZIP Code 60521 · Hinsdale, Illinois the single-name answer is the true one: Hinsdale Township High School District 86 holds all 6,472 homes counted there, and no other district holds a share worth naming.

In ZIP Code 60559 · Westmont, Illinois this district is one name among 6. Community High School District 99 leads with the largest share and Hinsdale Township High School District 86 holds 1,129 of the 10,807 homes counted there; no single name describes that area at all.

Hinsdale Township High School District 86 is not the name anyone would give for ZIP Code 60558 · Western Springs, Illinois — Lyons Township High School District 204 leads it — and Hinsdale Township High School District 86 holds 59 homes there all the same. Answer that area with one name and that is what it is wrong about.

The elementary districts that feed it

Students arrive at Hinsdale Township High School District 86 from 6 districts that run the lower grades on the same ground — Hinsdale Community Consolidated School District 181, which sends 29%, Maercker School District 60, which sends 14% and Gower School District 62, which sends 12%. Each of those addresses therefore belongs to two districts at once, one for grade school and this one for high school, and neither name is the whole answer.

• Hinsdale Community Consolidated School District 18129% of Hinsdale Township High School District 86's homes come from here
• Maercker School District 6014% of Hinsdale Township High School District 86's homes come from here
• Gower School District 6212% of Hinsdale Township High School District 86's homes come from here
• Darien School District 6111% of Hinsdale Township High School District 86's homes come from here
• Community Consolidated School District 1808.3% of Hinsdale Township High School District 86's homes come from here
• Cass School District 637.8% of Hinsdale Township High School District 86's homes come from here

The names in this list are exact: the federal file gives the district of each band for every census block. The percentages are not. They spread each shared ZIP Code area's homes across the other band in proportion to the share each district holds there, because the file names the two districts of a block and not how a household moves between them. Read them as the size of the crossing, not as a count of houses.

Who it shares ZIP Codes with

Hinsdale Township High School District 86 shares ZIP Code areas with 21 different districts. The most frequent are Hinsdale Community Consolidated School District 181, Maercker School District 60, Community High School District 99 and Darien School District 61. In a neighborhood this crowded the question is not which district serves the ZIP Code but which side of which street an address is on.

• Hinsdale Community Consolidated School District 1815 shared ZIP areas
• Maercker School District 605 shared ZIP areas
• Community High School District 993 shared ZIP areas
• Darien School District 613 shared ZIP areas
• Westmont Community Unit School District 2013 shared ZIP areas
• Butler School District 532 shared ZIP areas

Where this district sits

• School districts in Illinois1,034 of 1,394 ZIP areas split
• Every district with a page here260 districts listed

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: in 7 of the 9 ZIP Code areas Hinsdale Township High School District 86 reaches, at least one other district holds a real share of the homes as well, and the line between 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 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.

Where these numbers come from

School district boundaries come from the Census Bureau's Census Geographic Relationship File, current 2026 vintage, which assigns every census block to a unified district or to an elementary and a secondary district. Homes and residents in each block come from the 2020 Census Redistricting Data (PL 94-171), H1_001 and P1_001. The ZIP Code areas come from the same Geographic Relationship File, block to ZIP Code Tabulation Area. District names and grade ranges come from the Census Gazetteer 2025, with 2020 for districts no longer listed.

The place name printed beside a ZIP Code comes from the Census 2020 ZIP Code Tabulation Area relationship files: place, county subdivision and county, taken 2026-09-06. It is a label rather than a measurement: the Census Bureau does not publish which post office a ZIP Code belongs to, so the place named is the one covering the most land inside the area, not the city the Postal Service prints on an envelope.

Everything else on this page — the shares, the counts of districts per ZIP, the comparison between the two grade bands, the rankings — is computed here from those files. The source publishes none of it. Snapshot taken 2026-09-03.