County facts · Population growth · October 23, 2026
Fastest Growing Counties in Utah, 2020 to 2025
Utah's fastest growing counties by percent and by people added, April 2020 to July 2025 Census estimates, with each official parcel map.
Looking for the fastest growing counties in Utah? From the Census Bureau's April 1, 2020 estimates base to its July 1, 2025 estimate, Utah went from about 3,271,601 to 3,538,904 residents, a change of +267,303 (+8.2%). The fastest growing county by percentage was Tooele County (+20.3%), while Utah County added the most people (+100,467, +15.2%).
Every row below links to the county's Platbookmapper page and straight to its official parcel viewer, handy if growth is why you are looking at land there.
Utah growth at a glance
- County: 29
- Statewide, April 2020 to July 2025: +267,303 residents (+8.2%); July 2024 to July 2025 alone: +35,921 (+1.0%)
- Grew: 28 of 29 · Lost residents: 1
- Fastest growing by percent: Tooele County (+20.3%); most people added: Utah County (+100,467)
- Counties with more deaths than births over the period: 6 of 29
The 10 fastest growing Utah counties by percent
| # | County | Apr 2020 | Jul 2025 | Change | % change | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Tooele County | 72,703 | 87,461 | +14,758 | +20.3% | ArcGIS Web AppBuilder |
| 2 | Washington County | 180,284 | 213,670 | +33,386 | +18.5% | county web map |
| 3 | Iron County | 57,272 | 67,141 | +9,869 | +17.2% | ArcGIS Experience Builder |
| 4 | Utah County | 659,392 | 759,859 | +100,467 | +15.2% | county web map |
| 5 | Juab County | 11,780 | 13,567 | +1,787 | +15.2% | Utah State Parcels viewer |
| 6 | Box Elder County | 57,668 | 65,320 | +7,652 | +13.3% | ArcGIS Experience Builder |
| 7 | Kane County | 7,671 | 8,597 | +926 | +12.1% | listed link under review |
| 8 | Wasatch County | 34,785 | 38,514 | +3,729 | +10.7% | ArcGIS Experience Builder |
| 9 | Sanpete County | 28,437 | 31,453 | +3,016 | +10.6% | Utah State Parcels viewer |
| 10 | Cache County | 133,158 | 145,000 | +11,842 | +8.9% | ArcGIS Experience Builder |
These 10 added about 187,432 people combined. The median county changed by +6.4%.
The 10 counties that added the most people
| # | County | People added | % change | Jul 2025 | Parcel viewer |
|---|---|---|---|---|---|
| 1 | Utah County | +100,467 | +15.2% | 759,859 | county web map |
| 2 | Salt Lake County | +35,681 | +3.0% | 1,220,916 | county web map |
| 3 | Washington County | +33,386 | +18.5% | 213,670 | county web map |
| 4 | Davis County | +18,551 | +5.1% | 381,227 | county web map |
| 5 | Weber County | +15,950 | +6.1% | 278,174 | county web map |
| 6 | Tooele County | +14,758 | +20.3% | 87,461 | ArcGIS Web AppBuilder |
| 7 | Cache County | +11,842 | +8.9% | 145,000 | ArcGIS Experience Builder |
| 8 | Iron County | +9,869 | +17.2% | 67,141 | ArcGIS Experience Builder |
| 9 | Box Elder County | +7,652 | +13.3% | 65,320 | ArcGIS Experience Builder |
| 10 | Wasatch County | +3,729 | +10.7% | 38,514 | ArcGIS Experience Builder |
The top 10 account for about 94% of all the gains in the counties that grew.
Where the new residents came from
The Census Bureau splits each change into natural change (births minus deaths), net domestic migration (moves from other parts of the US) and net international migration. Totals for April 2020 to July 2025 in the five fastest growing counties:
| County | Births minus deaths | Net domestic moves | Net international moves | Total change |
|---|---|---|---|---|
| Tooele County | +3,189 | +10,885 | +730 | +14,758 |
| Washington County | +2,522 | +29,610 | +1,678 | +33,386 |
| Iron County | +2,074 | +7,103 | +753 | +9,869 |
| Utah County | +46,799 | +35,098 | +18,555 | +100,467 |
| Juab County | +635 | +1,110 | +43 | +1,787 |
In 4 of these 5, moves from elsewhere in the US were the biggest source of growth. The three parts do not add up exactly to the total because the Census Bureau also carries a small residual.
The last year alone: July 2024 to July 2025
- Tooele County: +3.1% (+2,633)
- Washington County: +2.5% (+5,239)
- Iron County: +2.4% (+1,582)
- Box Elder County: +2.1% (+1,335)
- Morgan County: +2.1% (+273)
4 of these 5 are also in the 2020–2025 top 10, so the growth is not a one-year blip.
Counties losing residents
1 of Utah's 29 counties had fewer residents in July 2025 than in April 2020. It is:
- Daggett County: −0.2% (−2, now about 934)
What fast growth means on a parcel map
- New lots show up as plats first. When land is subdivided, the plat is recorded with the county and the parcel layer catches up on its own schedule, so a brand-new lot may not appear on the map for a while. Check the recorder's recent plats if a parcel looks missing.
- Parcel numbers change after splits. A tract that was one parcel last year can be several today. Search by owner name or address as well as by an old parcel number.
- City limits move. Growing cities annex land, which changes who handles zoning and permits even though the county still keeps the deed and the tax map.
- Percent is not the same as people. A small county can post a big percentage on a modest number of new residents, so read the people-added column too.
Related guides
- Largest counties in Utah
- Utah county GIS websites by viewer
- Utah parcel map guide
- Utah statewide parcel map
- Utah landowner maps for hunting
- Fastest growing counties in the US
- US counties losing population
More: All Utah counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Percent change is from the April 1, 2020 estimates base to the July 1, 2025 estimate.
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 23, 2026) for each official parcel viewer.