Duval County
Florida · County seat: Jacksonville · County equivalent (e.g. borough in AK, parish in LA)
FIPS code 12031 is Duval County, Florida. With a population of 995,708 (2022 ACS estimate), it ranks #6 in Florida and #50 nationally. Duval County is part of the Jacksonville, FL. The state FIPS code for Florida is 12. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
12031
Population
995,708
2022 ACS · #50 nationally
Density
1,306.4/mi²
people per sq mile
Land Area
762
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 12031 is formed by combining the 2-digit state identifier 12 (Florida) with the 3-digit county identifier 031. Together they uniquely identify Duval County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 12031
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 12031.
Median Household Income
$65,579
ACS B19013_001E
Poverty Rate
14.3%
ACS B17001 (below poverty level)
Median Age
36.6
ACS B01002_001E
Metropolitan Area
Adjacent Counties (4)
Counties that share a border with Duval County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 12031.
Federal Datasets Using Code 12031
FIPS code 12031 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 12031 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:031",
"in": "state:12",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Duval County, Florida, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '12031';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '12'
AND county_fips = '031';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 12031 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "12",
county = "031",
year = 2022
)ZIP Codes in Duval 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 Duval County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 32277 | 100.0% |
| 32202 | 100.0% |
| 32203 | 100.0% |
| 32204 | 100.0% |
| 32205 | 100.0% |
| 32206 | 100.0% |
| 32207 | 100.0% |
| 32208 | 100.0% |
| 32209 | 100.0% |
| 32210 | 100.0% |
| 32211 | 100.0% |
| 32212 | 100.0% |
| 32214 | 100.0% |
| 32216 | 100.0% |
| 32217 | 100.0% |
| 32218 | 100.0% |
| 32219 | 100.0% |
| 32220 | 100.0% |
| 32221 | 100.0% |
| 32222 | 100.0% |
| 32223 | 100.0% |
| 32256 | 100.0% |
| 32257 | 100.0% |
| 32258 | 100.0% |
| 32266 | 100.0% |
| 32225 | 100.0% |
| 32226 | 100.0% |
| 32227 | 100.0% |
| 32228 | 100.0% |
| 32233 | 100.0% |
Showing top 30 of 38 ZIP codes by residential address share.