Rockcastle County area

Population and density of Rockcastle County

The Census Bureau estimates that 16,148 people lived in Rockcastle County on July 1, 2025. That ranks #2,098 of 3,222 county equivalents nationally and #71 of 120 in Kentucky. Since the April 1, 2020 estimates base of 16,033, the population has grown by 115 (+0.7%), compared with +2.2% for Kentucky as a whole.

With 316.6 square miles of land, that is 51 people per square mile (20 per km²), placing Rockcastle County #1,525 nationally for density and #70 in Kentucky. The median county equivalent has 47 people per square mile; the Kentucky median is 59. Put another way, there are about 13 acres of land per resident.

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 Rockcastle County

3 incorporated places lie at least partly in Rockcastle County. Together they are home to 3,736 people (23.1%); the other 12,412 (76.9%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Mount Vernon city, with 2,455 residents in the county. Among places with at least 1,000 residents in 2020, Mount Vernon city grew fastest since then (+0.3%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Rockcastle County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Rockcastle County is an outlying county of the Richmond-Berea, KY Micropolitan Statistical Area. Its 3 county equivalents have 131,806 residents on 1,007.6 square miles of land; Rockcastle County accounts for 31.4% of the land and 12.3% of the residents. By combined land it ranks #179 of 542 micropolitan areas, and #12 by population. It belongs to the Lexington-Fayette--Richmond--Frankfort, KY Combined Statistical Area.

ZIP codes

7 ZIP Code Tabulation Areas have land in Rockcastle County; 4 of them have most of their land inside the county, and the others mainly cover neighboring areas.

40403404094041940445404474045640460

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 Rockcastle County

Rockcastle County shares a land border with 6 county equivalents. It has more land than 1 of them. The largest neighbor is Pulaski County (658.1 mi²) and the smallest is Garrard County (229.9 mi²). Together with its neighbors, Rockcastle County forms a block of 2,754.4 mi² of land, of which it holds 11.5%.

How big is Rockcastle County compared with U.S. states?

Rockcastle County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 3.3 times as much. Kentucky’s county land could hold about 125 areas the size of Rockcastle County.

Another way to picture it: the same land area would fill a square about 17.8 miles (28.6 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 Rockcastle County?

Rockcastle County has more land than 452 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 Rockcastle County at #2,808 nationally by total area, 38 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 0.5%, compared with a national county-equivalent median of 1.2% — 0.7 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 Rockcastle County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.