Knox County area

Knox County, Tennessee covers 525.9 square miles: 508.4 square miles of land and 17.5 square miles of water. Its county seat is Knoxville. An estimated 511,453 people lived there in 2025.

Official Census measurements · GEOID 470932026 Gazetteer · retrieved September 27, 2026
Land area508.4 mi²
Water area17.5 mi²
Population (2025)511,453
People per mi²1,006

County outline

Generalized outline of Knox County, Tennessee
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Knox County is located

Knox County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 96.7% of Knox County’s measured area and water for 3.3%. Its combined area converts to 1,362 square kilometers or approximately 336,562 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land508.3861,316.714325,367
Water17.49245.30411,194.9
Total525.8781,362.018336,561.9

How Knox County compares

By original Census land area, Knox County ranks #36 of 95 in Tennessee and #2042 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.166 times the Tennessee county-equivalent median of 436.1 square miles. It accounts for 1.2% of the combined county land area in the state.

See the complete Tennessee ranking · What counts as a county equivalent?

Population and density of Knox County

The Census Bureau estimates that 511,453 people lived in Knox County on July 1, 2025. That ranks #146 of 3,222 county equivalents nationally and #3 of 95 in Tennessee. Since the April 1, 2020 estimates base of 478,925, the population has grown by 32,528 (+6.8%), compared with +5.8% for Tennessee as a whole.

With 508.4 square miles of land, that is 1,006 people per square mile (388 per km²), placing Knox County #189 nationally for density and #3 in Tennessee. The median county equivalent has 47 people per square mile; the Tennessee median is 76. Put another way, there are about 0.636 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate480,472486,009495,827501,589507,597511,453
Change—+5,537+9,818+5,762+6,008+3,856

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 Knox County

2 incorporated places lie at least partly in Knox County. Together they are home to 227,142 people (44.4%); the other 284,311 (55.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Knoxville city, with 202,021 residents in the county. Among places with at least 1,000 residents in 2020, Farragut town grew fastest since then (+6.9%).

Incorporated placePopulation 2025Since 2020Land mi²
Knoxville cityCounty seat202,021+6%98.8
Farragut townAlso in 1 other county25,121+6.9%16

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

Metropolitan area

Knox County is a central county of the Knoxville, TN Metropolitan Statistical Area. Its 9 county equivalents have 968,137 residents on 3,501 square miles of land; Knox County accounts for 14.5% of the land and 52.8% of the residents. By combined land it ranks #81 of 393 metropolitan areas, and #61 by population. It belongs to the Knoxville-Morristown-Sevierville, TN Combined Statistical Area.

County equivalentPopulation 2025Land mi²
Knox County511,453508.4
Blount County143,820558.8
Anderson County82,066337.2
Loudon County63,764229.3
Roane County57,395360.8
Campbell County40,290480.2
Grainger County25,739280.6
Morgan County22,160522.2
Union County21,450223.6

ZIP codes

31 ZIP Code Tabulation Areas have land in Knox County; 22 of them have most of their land inside the county, and the others mainly cover neighboring areas.

37709377213775437764377723777937806378073783037849378533787137902379093791237914379153791637917379183791937920379213792237923379243792937931379323793437938

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 Knox County

Knox County shares a land border with 8 county equivalents. It has more land than 6 of them. The largest neighbor is Sevier County (592.5 mi²) and the smallest is Union County (223.6 mi²). Together with its neighbors, Knox County forms a block of 3,366.3 mi² of land, of which it holds 15.1%.

Map of Knox County and the 8 county equivalents that border it Anderson County, Tennessee: 337.2 mi² landBlount County, Tennessee: 558.8 mi² landSevier County, Tennessee: 592.5 mi² landUnion County, Tennessee: 223.6 mi² landLoudon County, Tennessee: 229.3 mi² landGrainger County, Tennessee: 280.6 mi² landJefferson County, Tennessee: 275.2 mi² landRoane County, Tennessee: 360.8 mi² land
Knox County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. KnoxCompare
Sevier County592.51.2× largerCompare
Blount County558.81.1× largerCompare
Roane County360.81.4× smallerCompare
Anderson County337.21.5× smallerCompare
Grainger County280.61.8× smallerCompare
Jefferson County275.21.8× smallerCompare
Loudon County229.32.2× smallerCompare
Union County223.62.3× smallerCompare

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

Knox County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2 times as much. Tennessee’s county land could hold about 81 areas the size of Knox County.

Land area: Knox County and the closest-sized states
Knox County508.4 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 22.5 miles (36.3 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 Knox County?

Knox County has more land than 1,180 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Knox County508.4 mi²
Tennessee median436.1 mi²
National median604.5 mi²

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 Knox County at #2,089 nationally by total area, 47 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 3.3%, compared with a national county-equivalent median of 1.2% — 2.2 percentage points higher. 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 Knox County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2041St. Louis County, Missouri508.5Compare
#2042Knox County, Tennessee508.4This county
#2043Coles County, Illinois508.3Compare

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 35.992726, -83.937721. 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: 1,316,714,711 m²; AWATER: 45,302,804 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Knox County?

Knox County, Tennessee has 508.4 square miles (1,316.7 km²) of land and 17.5 square miles of water, for a total area of 525.9 square miles. It ranks #2042 of 3,222 U.S. county equivalents by land area.

Is Knox County the largest county in Tennessee?

No. Knox County ranks #36 of 95 in Tennessee by land area. The largest is Shelby County, with 752.8 square miles of land.

What counties border Knox County?

Knox County shares a land border with Anderson County, Blount County, Sevier County, Union County, Loudon County, Grainger County, Jefferson County, and Roane County.

What is the population of Knox County?

The Census Bureau estimates Knox County had 511,453 residents on July 1, 2025, ranking #146 of 3,222 county equivalents. That is 1,006 people per square mile of land.

What is the county seat of Knox County?

The county seat of Knox County is Knoxville.

What cities and towns are in Knox County?

Knox County has 2 incorporated places. The most populous are Knoxville city and Farragut town; 284,311 residents live outside any incorporated place.

Is Knox County part of a metropolitan area?

Yes. It is a central county of the Knoxville, TN Metropolitan Statistical Area, which has 9 county equivalents and 968,137 residents.

How many ZIP codes are in Knox County?

31 ZIP Code Tabulation Areas have land in Knox County, and 22 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Knox County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 2 times as much land.

How many acres of land are in Knox County?

The land measurement converts to approximately 325,367 acres. Including water, total area is approximately 336,562 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.

Cite this county

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