Idaho Counties
Complete list of all 44 counties in Idaho with population, area, median income, and county seats — plus a free printable blank map.
Labeled outline map of Idaho counties. Download a printable version in SVG, PNG, or PDF.
All 43 Idaho counties
| County | County Seat | Population ▼ | Area | Median Income | Cities |
|---|---|---|---|---|---|
| Ada | — | 500,759 | 1,053 mi² | $92,782 | 7 |
| Canyon | — | 249,392 | 587 mi² | $78,659 | 8 |
| Kootenai | — | 184,228 | 1,244 mi² | $82,276 | 10 |
| Twin Falls | — | 95,212 | 1,921 mi² | $67,710 | 8 |
| Bannock | — | 72,824 | 1,112 mi² | $68,792 | 7 |
| Madison | — | 56,613 | 469 mi² | $59,693 | 4 |
| Elmore | — | 49,625 | 3,075 mi² | $92,550 | 6 |
| Bonner | — | 48,468 | 1,735 mi² | $69,920 | 17 |
| Bingham | — | 48,339 | 2,094 mi² | $78,745 | 10 |
| Nez Perce | — | 43,845 | 848 mi² | $71,921 | 8 |
| Latah | — | 40,960 | 1,076 mi² | $67,033 | 10 |
| Jefferson | — | 32,160 | 1,094 mi² | $86,940 | 7 |
| Cassia | — | 26,540 | 2,565 mi² | $70,347 | 7 |
| Power | — | 26,126 | 1,404 mi² | $59,412 | 4 |
| Payette | — | 25,676 | 407 mi² | $67,367 | 3 |
How many counties does Idaho have?
Idaho has 44 counties covering 82,644 square miles and roughly 1,803,111 residents. The state was admitted to the Union in 1890 as the 43rd state, and the current county boundaries reflect more than a century of administrative subdivision.
The largest county by land area is Idaho County at 8,477 square miles, home to about 18,759 residents. The most populous is Ada County with approximately 500,759 residents — a density of about 476 people per square mile.
At the other end of the scale, Clark County has only about 753 residents.
Boise is both the state capital and the largest city in Idaho.
Related resources
Download a printable outline of Idaho’s county boundaries from our blank map of Idaho page — available in SVG, PNG, and PDF.
Use the What County Am I In? tool to detect which Idaho county a GPS location or address falls in, or the Address to County Lookup for batch input.
For demographic radius analysis, the Find ZIP Codes in Radius and Population Within Radius tools let you draw a circle around any Idaho address and see every ZIP code and the total population inside.
Two SimpleMapLab studies cover Idaho specifically: the 100-mile radius around Boise measures how much of the state lives within 100 miles of its capitol, and the loneliest town in Idaho ranks the state’s most isolated inhabited place. The county-counts blog post puts Idaho’s 44 counties in national context.
Frequently asked questions
Population and demographics are aggregated from ZIP-code-level US Census data via the SimpleMaps dataset. Countiesboundaries are from the US Atlas TopoJSON build of the Census Bureau’s TIGER/Line shapefiles. Land area is from the Census Gazetteer. State counts follow the US Census Bureau’s definition of counties and county-equivalents (50 states + DC = 3,143). All sources are public domain.