ZIP Code 57440

ZIP code 57440 is classified by USPS as a standard delivery area and covers roughly 360.0 square miles in Frankfort, Spink County, South Dakota. The area is home to 612 residents, producing a population density of 2 people per square mile, and falls within the Chicago time zone. These USPS and Census boundary values drive every downstream statistic on this page, including the benchmarks that compare 57440 against South Dakota and the nation.

On the economic side, the median household income for ZIP 57440 sits at $54,625 (29% below the South Dakota average), while per-capita income is $36,929. The poverty rate stands at 18.5% and the unemployment rate at 7.9%. On housing, the median home value is $132,800 (31% below the state average) with median rent at — per month, and 97.5% of occupied units are owner-occupied — a direct signal of whether 57440 behaves more like a homeowner neighborhood or a renter-heavy ZIP.

Education and household profile round out the picture: 26.5% of adults hold a bachelor's degree or higher, the median age is 54.5, and the average commute is —. Use the benchmarks above to see where 57440 sits relative to South Dakota and the national baseline rather than viewing the numbers in isolation. Every figure is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates, HUD Fair Market Rents, and FHFA Home Price Index data — no estimates, no proprietary scoring. Verify with HUD →