FIPS code 53033 is King County, Washington. With a population of 2,254,371 (2022 ACS estimate), it ranks #1 in Washington and #13 nationally. King County is part of the Seattle-Tacoma-Bellevue, WA. The state FIPS code for Washington is 53. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
53033
Population
2,254,371
2022 ACS · #13 nationally
Density
1,065.6/mi²
people per sq mile
Land Area
2,116
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 53033 is formed by combining the 2-digit state identifier 53 (Washington) with the 3-digit county identifier 033. Together they uniquely identify King County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 53033
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 53033.
Median Household Income
$116,340
ACS B19013_001E
Poverty Rate
8.5%
ACS B17001 (below poverty level)
Median Age
37.2
ACS B01002_001E
Metropolitan Area
Adjacent Counties (6)
Counties that share a border with King County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 53033.
Federal Datasets Using Code 53033
FIPS code 53033 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 53033 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:033",
"in": "state:53",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [King County, Washington, income, pop, ...]
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '53033';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '53'
AND county_fips = '033';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 53033 is WRONG for this county
library(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "53",
county = "033",
year = 2022
)
ZIP Codes in King 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 King County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 98133 | 100.0% |
| 98002 | 100.0% |
| 98003 | 100.0% |
| 98004 | 100.0% |
| 98005 | 100.0% |
| 98006 | 100.0% |
| 98007 | 100.0% |
| 98008 | 100.0% |
| 98010 | 100.0% |
| 98011 | 100.0% |
| 98014 | 100.0% |
| 98019 | 100.0% |
| 98177 | 100.0% |
| 98178 | 100.0% |
| 98188 | 100.0% |
| 98195 | 100.0% |
| 98198 | 100.0% |
| 98199 | 100.0% |
| 98224 | 100.0% |
| 98288 | 100.0% |
| 98023 | 100.0% |
| 98024 | 100.0% |
| 98025 | 100.0% |
| 98027 | 100.0% |
| 98028 | 100.0% |
| 98029 | 100.0% |
| 98030 | 100.0% |
| 98031 | 100.0% |
| 98032 | 100.0% |
| 98033 | 100.0% |
Showing top 30 of 89 ZIP codes by residential address share.