Residential delivery area · Connecticut
ZIP Code 06437: Guilford, CT
ZIP code 06437 uses the postal name Guilford, Connecticut and lies entirely in New Haven County (Census 2020 ZIP-county file). About 22,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $137,615 (Census Bureau, ACS 2020-2024). By Census place, 5% of its land lies in Guilford Center (a census-designated place); 95% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Guilford · its only residential ZIP
- County
- New Haven County
- Census places
- Guilford Center census-designated place
- House district
- CT-3 119th Congress
- State
- Connecticut
- Time zone
- Eastern
- Land area
- 47.1 sq mi · 468 people per sq mi
Where is ZIP code 06437?
06437 centers on 41.332°, -72.697° and covers 47.1 square miles of land plus 1.6 of water. It borders 5 ZIP codes: 06443, 06471, 06472, 06405, 06422.
The map draws ZIP code areas only. For the streets inside 06437, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 06437 compare with the rest of New Haven County?
| Measure | 06437 | In New Haven County | In CT |
|---|---|---|---|
| People (ACS 2020-2024) | 22,067 | 17th of 41 | 56th of 288 |
| Median household income | $138k | 6th of 37 | 45th of 228 |
| Median home value | $515k | 3rd of 40 | 36th of 245 |
Its median household income is higher than in 95% of U.S. residential ZIP codes, and it is denser than 71% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 06437?
The 2020 Census counted 22,064 people in 06437; the ACS, which samples households over 2020-2024, estimates 22,067. Between the 2010 and 2020 censuses its population fell 1.4% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 22,067
- 2020 Census count
- 22,064−1.4% since 2010 (22,375)
- Households
- 8,856
- Median age
- 51.2
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 06437?
Of the 22,067 people the ACS estimates in 06437, 20.8% are under 18 and 26.7% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (82.8%).
- Under 1820.8%
- 18 to 6452.5%
- 65 and older26.7%
- White, not Hispanic82.8%
- Hispanic or Latino5.8%
- Other or two or more5.3%
- Asian, not Hispanic4.5%
- Black, not Hispanic1.6%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 06437 earn?
Median household income is $137,615 (ACS 2020-2024), the 6th highest of the 37 ranked ZIP codes in New Haven County. It is not measurably different from 2015-2019 ($137,263 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $137,615
- Income per person
- $73,108
- Below the poverty line
- 2.8%
- Unemployed (of the labor force)
- 4.9%
- Adults 25+ with a bachelor's degree
- 60.5%
- Adjusted gross income per tax return, 2022
- $168,07811,250 returns; wages 59% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 06437?
FHFA's house price index for 06437, built from repeat sales and appraisals of the same homes, rose 63% from 2015 to 2025 and rose 52% from 2020 to 2025, and moved +2.5% in 2025.
- Median home value (owners' estimate)
- $515,000
- Median gross rent
- $1,717
- Homes owned by their occupants
- 83.6%
- Housing units
- 9,825
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 06437?
669 business establishments had a location in this ZIP code in 2023, 22 more than in 2018; the most are in health care and social assistance (ZIP Code Business Patterns).
- Health care and social assistance107
- Retail trade82
- Professional, scientific, and technical services81
- Other services (except public administration)78
- Construction71
- Finance and insurance46
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 06437?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 06443 | Madison | 17,657 | $169k | 3.9 mi |
| 06471 | North Branford | 7,140 | $109k | 3.9 mi |
| 06472 | Northford | 6,363 | $106k | 5.8 mi |
| 06405 | Branford | 28,217 | $105k | 5.9 mi |
| 06422 | Durham | 7,208 | $159k | 9.5 mi |
| 06419 | Killingworth | 6,240 | $141k | 6.8 mi (near) |
| 06473 | North Haven | 24,743 | $133k | 9.0 mi (near) |
| 06513 | New Haven | 38,888 | $49k | 9.0 mi (near) |
| 06413 | Clinton | 13,377 | $125k | 9.1 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.