King County vs Snohomish County
Two neighbouring counties in Washington, compared on population, size, income and housing. They share 62 mi of border.
King County
Washington
Snohomish County
Washington
Both outlines are drawn at true relative size. Snohomish County spans about 119.4 km at its widest.
Side by side
| Measure | King County | Difference | Snohomish County |
|---|---|---|---|
| Population | 2,344,939 | +169.3% | 870,656 |
| Change since 2020 | 3.1% | -1.8 pp | 4.9% |
| Land area | 2,116 sq mi | +1.4% | 2,087 sq mi |
| Population density | 1,108 per sq mi | +165.7% | 417 per sq mi |
| Median household income | $124,746 | +12.1% | $111,246 |
| Median home value | $859,900 | +23.5% | $696,000 |
| Median age | 37.4 | -3.1% | 38.6 |
| Households | 941,054 | +197.6% | 316,212 |
| Housing units | 1,003,284 | +202.6% | 331,530 |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026; US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. The difference column is computed here: the first county's figure against the second, expressed as a percentage of the second. The change-since-2020 row is the exception: two growth rates differ in percentage points (pp), not percent. Retrieved 30 August 2026.
What the numbers say
- King County holds about 2.7 times the population of Snohomish County: 2,344,939 against 870,656.
- King County covers more ground, at 2,116 square miles against 2,087.
- King County is the more crowded of the two, at 1,108 people per square mile against 417.
- Median household income is higher in King County, by 13,500 dollars a year.
- Since 2020, King County has grown by 3.1% and Snohomish County has grown by 4.9%.
- They share 62 mi of common border, which the Census Bureau publishes in its county adjacency file and which almost no other county reference presents.
Full pages
Want a different pair? Compare any two of the 3,144 US counties.
Rebuilt from source data 30 August 2026. How these figures are produced.