UT · 2026 Census Gazetteer

Utah counties by area

Official, comparable measurements for 29 counties and county equivalents.

Source fields preservedGEOID · ALAND · AWATER
County equivalents29
Combined land82,595.6 mi²
Combined water2,302.5 mi²
Largest by landSan Juan County

Understanding Utah’s county areas

The land-area range runs from Davis County at 324.9 mi² to San Juan County at 7,823.7 mi². The largest has 24.1 times the land area of the smallest and accounts for 9.5% of the combined county land in Utah.

The median county-equivalent land area is 2,427.6 mi², above the national median of 604.5 mi². The median describes the middle of the county size distribution; it does not describe how people or development are distributed. A state with a few very large counties can have a much smaller median than its largest entry suggests.

Where water changes the picture

Box Elder County has the most assigned water area, at 947.9 mi². Davis County has the highest water share, with water making up 48.9% of its total area. Water area and water percentage answer different questions: the first measures an amount, while the second measures the mix of land and water.

Across all 29 entries, water accounts for 2.7% of the combined total area. This is calculated from the summed land and water measurements, rather than averaging county percentages, which would give each small and large county equal weight.

Compare the largest and smallest county equivalents in Utah to see land, water, and total area on the same scale.

These calculations use the 2026 Census county records listed below. County-equivalent boundaries vary between states; area alone does not measure population, density, or usable land. See coverage and calculation rules.

Complete area table

Sorted from largest to smallest land area.

#County / equivalentLandWaterWater share
1San Juan CountyGEOID 490377,823.7 mi²110.1 mi²1.4%
2Tooele CountyGEOID 490457,040.3 mi²245.7 mi²3.4%
3Millard CountyGEOID 490276,785.5 mi²51.5 mi²0.8%
4Box Elder CountyGEOID 490035,781.3 mi²947.9 mi²14.1%
5Garfield CountyGEOID 490175,179.6 mi²29.3 mi²0.6%
6Uintah CountyGEOID 490474,482.9 mi²21.6 mi²0.5%
7Emery CountyGEOID 490154,462.6 mi²9.5 mi²0.2%
8Kane CountyGEOID 490253,994.1 mi²113.1 mi²2.8%
9Grand CountyGEOID 490193,672.9 mi²11.8 mi²0.3%
10Juab CountyGEOID 490233,391.8 mi²14 mi²0.4%
11Iron CountyGEOID 490213,296.2 mi²4.4 mi²0.1%
12Duchesne CountyGEOID 490133,235.5 mi²15 mi²0.5%
13Beaver CountyGEOID 490012,582.9 mi²2 mi²0.1%
14Wayne CountyGEOID 490552,461.1 mi²5.7 mi²0.2%
15Washington CountyGEOID 490532,427.6 mi²3 mi²0.1%
16Utah CountyGEOID 490492,004.5 mi²139.8 mi²6.5%
17Sevier CountyGEOID 490411,910.5 mi²7.8 mi²0.4%
18Summit CountyGEOID 490431,870.7 mi²10 mi²0.5%
19Sanpete CountyGEOID 490391,589.8 mi²12.4 mi²0.8%
20Carbon CountyGEOID 490071,479.3 mi²6 mi²0.4%
21Wasatch CountyGEOID 490511,177 mi²30.5 mi²2.5%
22Cache CountyGEOID 490051,164.7 mi²8.2 mi²0.7%
23Rich CountyGEOID 490331,028.8 mi²57.6 mi²5.3%
24Piute CountyGEOID 49031758.2 mi²7.8 mi²1%
25Salt Lake CountyGEOID 49035752.7 mi²52.8 mi²6.6%
26Daggett CountyGEOID 49009696.5 mi²23.6 mi²3.3%
27Weber CountyGEOID 49057611 mi²48.9 mi²7.4%
28Morgan CountyGEOID 49029609.2 mi²1.7 mi²0.3%
29Davis CountyGEOID 49011324.9 mi²310.5 mi²48.9%
How to read this table. Land and water areas are Census statistical measurements in square miles. Adding county rows can differ slightly from separately published state totals because of rounding and geographic treatment.