County outline
Where Bastrop County is located
Area breakdown
Land accounts for 99.2% of Bastrop County’s measured area and water for 0.8%. Its combined area converts to 2,319.5 square kilometers or approximately 573,164 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 888.227 | 2,300.497 | 568,465.3 |
| Water | 7.341 | 19.013 | 4,698.2 |
| Total | 895.568 | 2,319.51 | 573,163.5 |
How Bastrop County compares
By original Census land area, Bastrop County ranks #163 of 254 in Texas and #895 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.977 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 Bastrop County
The Census Bureau estimates that 118,908 people lived in Bastrop County on July 1, 2025. That ranks #547 of 3,222 county equivalents nationally and #42 of 254 in Texas. Since the April 1, 2020 estimates base of 97,229, the population has grown by 21,679 (+22.3%), compared with +8.8% for Texas as a whole.
With 888.2 square miles of land, that is 134 people per square mile (52 per km²), placing Bastrop County #827 nationally for density and #42 in Texas. The median county equivalent has 47 people per square mile; the Texas median is 22. Put another way, there are about 4.8 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 98,060 | 102,270 | 106,581 | 111,561 | 115,937 | 118,908 |
| Change | — | +4,210 | +4,311 | +4,980 | +4,376 | +2,971 |
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 Bastrop County
5 incorporated places lie at least partly in Bastrop County. Together they are home to 29,162 people (24.5%); the other 89,746 (75.5%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Bastrop city, with 13,383 residents in the county. By land, Austin city is the largest at 324.8 mi² across all its counties. Among places with at least 1,000 residents in 2020, Elgin city grew fastest since then (+40%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Bastrop cityCounty seat | 13,383 | +38.2% | 9.842 |
| Elgin cityAlso in 1 other county | 11,412 | +40% | 7.256 |
| Smithville city | 4,367 | +8.4% | 4.136 |
| Austin cityAlso in 3 other counties | 0 | — | 324.8 |
| Mustang Ridge cityAlso in 2 other counties | 0 | — | 3.729 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Bastrop County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Bastrop County is an outlying county of the Austin-Round Rock-San Marcos, TX Metropolitan Statistical Area. Its 5 county equivalents have 2,620,945 residents on 4,219.9 square miles of land; Bastrop County accounts for 21% of the land and 4.5% of the residents. By combined land it ranks #67 of 393 metropolitan areas, and #25 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Travis County | 1,389,670 | 994.4 |
| Williamson County | 752,827 | 1,115.9 |
| Hays County | 304,390 | 676.9 |
| Bastrop County | 118,908 | 888.2 |
| Caldwell County | 55,150 | 544.5 |
ZIP codes
15 ZIP Code Tabulation Areas have land in Bastrop County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.
786027861278616786177862178650786537865978662789417894278945789537895778959
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 Bastrop County
Bastrop County shares a land border with 5 county equivalents. It has more land than 2 of them. The largest neighbor is Williamson County (1,115.9 mi²) and the smallest is Caldwell County (544.5 mi²). Together with its neighbors, Bastrop County forms a block of 5,122 mi² of land, of which it holds 17.3%.
| Bordering county equivalent | Land mi² | Size vs. Bastrop | Compare |
|---|---|---|---|
| Williamson County | 1,115.9 | 1.3× larger | Compare |
| Travis County | 994.4 | 1.1× larger | Compare |
| Fayette County | 949.9 | 1.1× larger | Compare |
| Lee County | 629.1 | 1.4× smaller | Compare |
| Caldwell County | 544.5 | 1.6× smaller | Compare |
How big is Bastrop County compared with U.S. states?
Bastrop 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 294 areas the size of Bastrop County.
Another way to picture it: the same land area would fill a square about 29.8 miles (48 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 Bastrop County?
Bastrop County has more land than 2,327 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 Bastrop County at #993 nationally by total area, 98 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 0.8%, compared with a national county-equivalent median of 1.2% — 0.3 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 Bastrop County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #894 | Terry County, Texas | 888.9 | Compare |
| #895 | Bastrop County, Texas | 888.2 | This county |
| #896 | Wilcox County, Alabama | 887.9 | 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 30.100772, -97.310639. 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: 2,300,496,000 m²; AWATER: 19,013,900 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 Bastrop County?
Bastrop County, Texas has 888.2 square miles (2,300.5 km²) of land and 7.341 square miles of water, for a total area of 895.6 square miles. It ranks #895 of 3,222 U.S. county equivalents by land area.
Is Bastrop County the largest county in Texas?
No. Bastrop County ranks #163 of 254 in Texas by land area. The largest is Brewster County, with 6,183.8 square miles of land.
What counties border Bastrop County?
Bastrop County shares a land border with Lee County, Travis County, Caldwell County, Fayette County, and Williamson County.
What is the population of Bastrop County?
The Census Bureau estimates Bastrop County had 118,908 residents on July 1, 2025, ranking #547 of 3,222 county equivalents. That is 134 people per square mile of land.
What is the county seat of Bastrop County?
The county seat of Bastrop County is Bastrop.
What cities and towns are in Bastrop County?
Bastrop County has 5 incorporated places. The most populous are Bastrop city, Elgin city, Smithville city, Austin city, and Mustang Ridge city; 89,746 residents live outside any incorporated place.
Is Bastrop County part of a metropolitan area?
Yes. It is an outlying county of the Austin-Round Rock-San Marcos, TX Metropolitan Statistical Area, which has 5 county equivalents and 2,620,945 residents.
How many ZIP codes are in Bastrop County?
15 ZIP Code Tabulation Areas have land in Bastrop County, and 8 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Bastrop 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 Bastrop County?
The land measurement converts to approximately 568,465 acres. Including water, total area is approximately 573,164 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.