| ZIP Codes: | 33 ZIP Codes (29 Standard, 3 PO Box, 1 Unique) [See All] |
| Area Codes: | 224 / 312 / 464 / 630 / 708 / 815 / 847 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:12:01 PM |
| Population: | 747,565 [See All] |
| FIPS: | 17097 |
| CBSA: | Chicago-Naperville-Elgin, IL-IN |
| Land Area: | 506 sq mi |
| Water Area: | 38 sq mi |
| Coordinates: | 42.3076, -87.9625 |
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747,565 residents live across 33 ZIPs covering 506 sq mi, served by 29 distinct USPS-recognized cities.
Population moved from 736,457 to 747,436 from 2014 to 2024 — a +1.5% change. 16 ZIPs gained residents, 12 lost.
The county's wealthiest ZIP 60045 (Lake Forest, $233,125 median) and poorest ZIP 60064 (North Chicago, $49,195) are 5.6 miles apart — a 4.7× income gap across local geography.
Median home values vary 6.1× across this county — from $152,200 in 60064 (North Chicago) to $923,500 in 60045 (Lake Forest).
Density varies 20× across the county — from 397 people/sq mi in 60083 (Wadsworth) to 7,998 in 60040 (Highwood).
Educational attainment ranges from 15.5% bachelor's+ in 60099 (Zion) to 81.2% in 60045 (Lake Forest) — the breadth of educational profiles across the area.
Within Illinois, this is the #3 most populous of 102 counties and ranks #2 for median household income .
On the national stage, Lake County is the #88 most populous US county , ranks #92 for income .
Hosts 1 single-entity Unique ZIP: 60086Selective Service .
Weighted by population, the typical household earns about $121,078 across the county — reflecting what a typical resident sees, not a simple ZIP average.
48.4% of adults age 25+ hold a bachelor's degree or higher (241,604 of 498,847 reporting).
29 Standard delivery, 3 PO Box only, 1 single-entity Unique ZIPs serve this county.
10 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
Median household income spans 4.7× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 60085 | Waukegan | Standard | 72,341 | $66,793 | 14.8 | 1.7% |
| 60073 | Round Lake | Standard | 62,868 | $98,514 | 20.2 | 3.1% |
| 60010 | Barrington | Standard | 45,747 | $177,566 | 76.4 | 3.0% |
| 60047 | Lake Zurich | Standard | 44,240 | $176,081 | 34.7 | 4.8% |
| 60089 | Buffalo Grove | Standard | 42,872 | $129,401 | 10.1 | 3.1% |
| 60060 | Mundelein | Standard | 37,344 | $110,335 | 25.7 | -1.6% |
| 60031 | Gurnee | Standard | 37,107 | $111,034 | 18.5 | -2.1% |
| 60030 | Grayslake | Standard | 35,792 | $104,795 | 28.7 | -2.1% |
| 60046 | Lake Villa | Standard | 34,613 | $126,042 | 27.1 | -0.7% |
| 60099 | Zion | Standard | 30,881 | $66,109 | 24.6 | -2.6% |
| 60035 | Highland Park | Standard | 30,398 | $168,094 | 12.6 | 1.9% |
| 60048 | Libertyville | Standard | 29,124 | $173,975 | 28.1 | -0.5% |
| 60015 | Deerfield | Standard | 28,096 | $183,125 | 13.9 | 2.6% |
| 60061 | Vernon Hills | Standard | 27,974 | $124,468 | 8.5 | 7.0% |
| 60087 | Waukegan | Standard | 27,293 | $76,738 | 13.5 | 3.5% |
| 60002 | Antioch | Standard | 24,232 | $104,981 | 38.0 | -0.3% |
| 60045 | Lake Forest | Standard | 21,074 | $233,125 | 21.8 | 2.7% |
| 60084 | Wauconda | Standard | 17,192 | $110,090 | 15.4 | 8.4% |
| 60064 | North Chicago | Standard | 14,884 | $49,195 | 5.4 | -6.4% |
| 60088 | Great Lakes | Standard | 14,400 | $66,008 | 3.1 | 7.3% |
| 60020 | Fox Lake | Standard | 10,970 | $73,949 | 6.5 | 7.1% |
| 60044 | Lake Bluff | Standard | 10,312 | $134,724 | 7.0 | 6.5% |
| 60083 | Wadsworth | Standard | 9,981 | $123,125 | 25.1 | -3.9% |
| 60041 | Ingleside | Standard | 9,024 | $93,396 | 11.1 | 4.3% |
| 60069 | Lincolnshire | Standard | 8,502 | $162,826 | 5.5 | 2.4% |
| 60042 | Island Lake | Standard | 8,347 | $99,917 | 4.2 | -2.4% |
| 60096 | Winthrop Harbor | Standard | 6,527 | $95,601 | 4.5 | -5.5% |
| 60040 | Highwood | Standard | 5,301 | $107,875 | 0.7 | -1.8% |
| 60075 | Russell | PO Box | 129 | — | 0.0 | — |
| 60079 | Waukegan | PO Box | — | — | 0.0 | — |
| 60037 | Fort Sheridan | Standard | — | — | 0.2 | — |
| 60011 | Barrington | PO Box | — | — | 0.0 | — |
| 60086 | North Chicago | Unique | — | — | 0.0 | — |