Nicholas County
Kentucky · County seat: Carlisle · Active county or equivalent
FIPS code 21181 is Nicholas County, Kentucky. With a population of 7,613 (2022 ACS estimate), it ranks #110 in Kentucky and #2677 nationally. The state FIPS code for Kentucky is 21. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
21181
Population
7,613
2022 ACS · #2677 nationally
Density
39.0/mi²
people per sq mile
Land Area
195
sq miles
Urban/Rural
Nonmetro — rural, adjacent to metro
RUCC 8
How This FIPS Code Works
The 5-digit FIPS code 21181 is formed by combining the 2-digit state identifier 21 (Kentucky) with the 3-digit county identifier 181. Together they uniquely identify Nicholas County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 21181
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 21181.
Median Household Income
$57,539
ACS B19013_001E
Poverty Rate
16.2%
ACS B17001 (below poverty level)
Median Age
38.9
ACS B01002_001E
Adjacent Counties (6)
Counties that share a border with Nicholas County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 21181.
Federal Datasets Using Code 21181
FIPS code 21181 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 21181 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:181",
"in": "state:21",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Nicholas County, Kentucky, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '21181';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '21'
AND county_fips = '181';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 21181 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "21",
county = "181",
year = 2022
)ZIP Codes in Nicholas County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Nicholas County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 40350 | 100.0% |
| 40311 | 89.3% |
| 40374 | 11.6% |
| 41039 | 10.7% |
| 41031 | 5.7% |
| 40361 | 0.3% |