Residential delivery area · Iowa
ZIP Code 51240: Inwood, IA
ZIP code 51240 uses the postal name Inwood, Iowa and lies mostly in Lyon County (85% of its land) with the rest in Sioux County (Census 2020 ZIP-county file). About 1,900 people live there (Census Bureau, ACS 2020-2024). Median household income is $83,929 (Census Bureau, ACS 2020-2024). By Census place, 1% of its land lies in Inwood; 99% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Inwood · its only residential ZIP
- County
- Lyon County (85%); Sioux County (15%)
- Census places
- Inwood
- House district
- IA-4 119th Congress
- State
- Iowa
- Time zone
- Central
- Land area
- 100.4 sq mi · 19 people per sq mi
Where is ZIP code 51240?
51240 centers on 43.309°, -96.458° and covers 100.4 square miles of land plus 0.1 of water. It borders 6 ZIP codes: 51230, 57013, 57027, 51241, 51247, 51235.
The map draws ZIP code areas only. For the streets inside 51240, 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 51240 compare with the rest of Lyon County?
| Measure | 51240 | In Lyon County | In IA |
|---|---|---|---|
| People (ACS 2020-2024) | 1,914 | 6th of 12 | 290th of 970 |
| Median household income | $84k | 2nd of 7 | 145th of 396 |
| Median home value | $233k | 6th of 8 | 119th of 423 |
Its median household income is higher than in 67% of U.S. residential ZIP codes, and it is denser than 25% 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 51240?
The 2020 Census counted 1,816 people in 51240; the ACS, which samples households over 2020-2024, estimates 1,914. Between the 2010 and 2020 censuses its population grew 4.0% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 1,914±297 (90% margin)
- 2020 Census count
- 1,816+4.0% since 2010 (1,746)
- Households
- 632
- Median age
- 34.4
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 51240?
Of the 1,914 people the ACS estimates in 51240, 35.4% are under 18 and 19.6% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (94.4%).
- Under 1835.4%
- 18 to 6445.0%
- 65 and older19.6%
- White, not Hispanic94.4%
- Other or two or more2.0%
- Hispanic or Latino1.7%
- Asian, not Hispanic1.7%
- Black, not Hispanic0.3%
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 51240 earn?
Median household income is $83,929 (ACS 2020-2024), the 2nd highest of the 7 ranked ZIP codes in Lyon County. It is not measurably different from 2015-2019 ($84,467 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $83,929
- Income per person
- $41,804
- Below the poverty line
- 3.0%
- Unemployed (of the labor force)
- 1.4%
- Adults 25+ with a bachelor's degree
- 16.5%
- Adjusted gross income per tax return, 2022
- $93,213770 returns; wages 53% 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 51240?
FHFA's house price index for 51240, built from repeat sales and appraisals of the same homes, rose 170% from 2015 to 2025 and rose 103% from 2020 to 2025, and moved +24.6% in 2025.
- Median home value (owners' estimate)
- $232,600
- Median gross rent
- $993
- Homes owned by their occupants
- 86.9%
- Housing units
- 673
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 51240?
67 business establishments had a location in this ZIP code in 2023, 8 more than in 2018; the most are in construction (ZIP Code Business Patterns).
- Construction15
- Transportation and warehousing12
- Retail trade8
- Other services (except public administration)7
- Wholesale trade5
- Manufacturing4
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 51240?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 51230 | Alvord | 478 | $76k | 7.6 mi |
| 57013 | Canton, SD | 4,504 | $77k | 8.6 mi |
| 57027 | Fairview, SD | 199 | – | 8.7 mi |
| 51241 | Larchwood | 2,103 | $87k | 9.8 mi |
| 51247 | Rock Valley | 5,094 | $78k | 10.0 mi |
| 51235 | Doon | 1,007 | $71k | 12.3 mi |
| 51242 | Lester | 379 | $96k | 10.4 mi (near) |
| 57032 | Harrisburg, SD | 10,467 | $112k | 13.6 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.