County outline
Where Hamilton County is located
Area breakdown
Land accounts for 99.9% of Hamilton County’s measured area and water for 0.1%. Its combined area converts to 2,166.2 square kilometers or approximately 535,292 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 835.915 | 2,165.01 | 534,985.6 |
| Water | 0.478 | 1.238 | 305.9 |
| Total | 836.393 | 2,166.248 | 535,291.5 |
How Hamilton County compares
By original Census land area, Hamilton County ranks #190 of 254 in Texas and #1003 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.92 times the Texas county-equivalent median of 908.7 square miles. It accounts for 0.3% of the combined county land area in the state.
See the complete Texas ranking · What counts as a county equivalent?
Population and density of Hamilton County
The Census Bureau estimates that 8,680 people lived in Hamilton County on July 1, 2025. That ranks #2,592 of 3,222 county equivalents nationally and #175 of 254 in Texas. Since the April 1, 2020 estimates base of 8,224, the population has grown by 456 (+5.5%), compared with +8.8% for Texas as a whole.
With 835.9 square miles of land, that is 10 people per square mile (4 per km²), placing Hamilton County #2,633 nationally for density and #167 in Texas. The median county equivalent has 47 people per square mile; the Texas median is 22. Put another way, there are about 62 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 8,252 | 8,241 | 8,310 | 8,603 | 8,716 | 8,680 |
| Change | — | −11 | +69 | +293 | +113 | −36 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Hamilton County
3 incorporated places lie at least partly in Hamilton County. Together they are home to 4,646 people (53.5%); the other 4,034 (46.5%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Hamilton city, with 3,016 residents in the county. Among places with at least 1,000 residents in 2020, Hico city grew fastest since then (+12.7%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Hamilton cityCounty seat | 3,016 | +4.3% | 3.467 |
| Hico cityAlso in 1 other county | 1,496 | +12.7% | 1.824 |
| Evant townAlso in 1 other county | 134 | +3.1% | 0.671 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Hamilton County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Hamilton County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
10 ZIP Code Tabulation Areas have land in Hamilton County; 5 of them have most of their land inside the county, and the others mainly cover neighboring areas.
76436764427645776525765317653876565765667663776844
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Hamilton County
Hamilton County shares a land border with 6 county equivalents. It has more land than 2 of them. The largest neighbor is Erath County (1,083.2 mi²) and the smallest is Lampasas County (712.5 mi²). Together with its neighbors, Hamilton County forms a block of 6,352.8 mi² of land, of which it holds 13.2%.
| Bordering county equivalent | Land mi² | Size vs. Hamilton | Compare |
|---|---|---|---|
| Erath County | 1,083.2 | 1.3× larger | Compare |
| Coryell County | 1,052.2 | 1.3× larger | Compare |
| Bosque County | 983 | 1.2× larger | Compare |
| Comanche County | 937.8 | 1.1× larger | Compare |
| Mills County | 748.2 | 1.1× smaller | Compare |
| Lampasas County | 712.5 | 1.2× smaller | Compare |
How big is Hamilton County compared with U.S. states?
Hamilton County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. Texas’s county land could hold about 313 areas the size of Hamilton County.
Another way to picture it: the same land area would fill a square about 28.9 miles (46.5 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Hamilton County?
Hamilton County has more land than 2,219 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Hamilton County at #1,106 nationally by total area, 103 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.1%, compared with a national county-equivalent median of 1.2% — 1.1 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Hamilton County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1002 | Huron County, Michigan | 835.9 | Compare |
| #1003 | Hamilton County, Texas | 835.9 | This county |
| #1004 | Will County, Illinois | 835.9 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 31.707342, -98.111756. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 2,165,008,740 m²; AWATER: 1,238,628 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Hamilton County?
Hamilton County, Texas has 835.9 square miles (2,165 km²) of land and 0.478 square miles of water, for a total area of 836.4 square miles. It ranks #1003 of 3,222 U.S. county equivalents by land area.
Is Hamilton County the largest county in Texas?
No. Hamilton County ranks #190 of 254 in Texas by land area. The largest is Brewster County, with 6,183.8 square miles of land.
What counties border Hamilton County?
Hamilton County shares a land border with Coryell County, Bosque County, Comanche County, Mills County, Erath County, and Lampasas County.
What is the population of Hamilton County?
The Census Bureau estimates Hamilton County had 8,680 residents on July 1, 2025, ranking #2,592 of 3,222 county equivalents. That is 10 people per square mile of land.
What is the county seat of Hamilton County?
The county seat of Hamilton County is Hamilton.
What cities and towns are in Hamilton County?
Hamilton County has 3 incorporated places. The most populous are Hamilton city, Hico city, and Evant town; 4,034 residents live outside any incorporated place.
Is Hamilton County part of a metropolitan area?
No. Hamilton County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Hamilton County?
10 ZIP Code Tabulation Areas have land in Hamilton County, and 5 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Hamilton County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.2 times as much land.
How many acres of land are in Hamilton County?
The land measurement converts to approximately 534,986 acres. Including water, total area is approximately 535,292 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.