County outline
Where Kay County is located
Area breakdown
Land accounts for 97.3% of Kay County’s measured area and water for 2.7%. Its combined area converts to 2,447.3 square kilometers or approximately 604,747 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 919.61 | 2,381.779 | 588,550.4 |
| Water | 25.307 | 65.545 | 16,196.5 |
| Total | 944.917 | 2,447.324 | 604,746.9 |
How Kay County compares
By original Census land area, Kay County ranks #28 of 77 in Oklahoma and #798 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.146 times the Oklahoma county-equivalent median of 802.7 square miles. It accounts for 1.3% of the combined county land area in the state.
See the complete Oklahoma ranking · What counts as a county equivalent?
Population and density of Kay County
The Census Bureau estimates that 43,490 people lived in Kay County on July 1, 2025. That ranks #1,146 of 3,222 county equivalents nationally and #23 of 77 in Oklahoma. Since the April 1, 2020 estimates base of 43,701, the population has declined by 211 (−0.5%), compared with +4.1% for Oklahoma as a whole.
With 919.6 square miles of land, that is 47 people per square mile (18 per km²), placing Kay County #1,609 nationally for density and #27 in Oklahoma. The median county equivalent has 47 people per square mile; the Oklahoma median is 28. Put another way, there are about 14 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 43,605 | 43,748 | 43,764 | 43,775 | 43,637 | 43,490 |
| Change | — | +143 | +16 | +11 | −138 | −147 |
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 Kay County
7 incorporated places lie at least partly in Kay County. Together they are home to 36,059 people (82.9%); the other 7,431 (17.1%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Ponca City city, with 24,225 residents in the county. The county seat, Newkirk city, has 2,246 residents.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Ponca City city | 24,225 | −0.8% | 17.8 |
| Blackwell city | 6,029 | −0.9% | 5.582 |
| Tonkawa city | 2,983 | −1.1% | 4.128 |
| Newkirk cityCounty seat | 2,246 | −0.1% | 1.355 |
| Kaw City city | 321 | +1.6% | 3.011 |
| Braman town | 163 | +0.6% | 0.196 |
| Kildare town | 92 | +2.2% | 0.136 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Kay County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Kay County is a central county of the Ponca City, OK Micropolitan Statistical Area. Kay County is the area’s only county equivalent, so the micro area has the same 919.6 square miles of land. By combined land it ranks #206 of 542 micropolitan areas, and #289 by population.
ZIP codes
10 ZIP Code Tabulation Areas have land in Kay County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
74601746047463174632746417464374646746477465274653
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 Kay County
Kay County shares a land border with 6 county equivalents, including 2 in Kansas. It has more land than 1 of them. The largest neighbor is Osage County (2,246.7 mi²) and the smallest is Noble County (731.7 mi²). Together with its neighbors, Kay County forms a block of 8,264.7 mi² of land, of which it holds 11.1%.
| Bordering county equivalent | Land mi² | Size vs. Kay | Compare |
|---|---|---|---|
| Osage County | 2,246.7 | 2.4× larger | Compare |
| Sumner CountyKansas | 1,181.7 | 1.3× larger | Compare |
| Cowley CountyKansas | 1,125.7 | 1.2× larger | Compare |
| Garfield County | 1,058.5 | 1.2× larger | Compare |
| Grant County | 1,000.7 | 1.1× larger | Compare |
| Noble County | 731.7 | 1.3× smaller | Compare |
How big is Kay County compared with U.S. states?
Kay County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.1 times as much. Oklahoma’s county land could hold about 75 areas the size of Kay County.
Another way to picture it: the same land area would fill a square about 30.3 miles (48.8 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 Kay County?
Kay County has more land than 2,424 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 Kay County at #856 nationally by total area, 58 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 2.7%, compared with a national county-equivalent median of 1.2% — 1.5 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 Kay County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #797 | Dundy County, Nebraska | 919.7 | Compare |
| #798 | Kay County, Oklahoma | 919.6 | This county |
| #799 | Collingsworth County, Texas | 918.4 | 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 36.814885, -97.143862. 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: 2,381,778,969 m²; AWATER: 65,545,115 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 Kay County?
Kay County, Oklahoma has 919.6 square miles (2,381.8 km²) of land and 25.3 square miles of water, for a total area of 944.9 square miles. It ranks #798 of 3,222 U.S. county equivalents by land area.
Is Kay County the largest county in Oklahoma?
No. Kay County ranks #28 of 77 in Oklahoma by land area. The largest is Osage County, with 2,246.7 square miles of land.
What counties border Kay County?
Kay County shares a land border with Osage County, Grant County, Noble County, Cowley County, Kansas, Sumner County, Kansas, and Garfield County.
What is the population of Kay County?
The Census Bureau estimates Kay County had 43,490 residents on July 1, 2025, ranking #1,146 of 3,222 county equivalents. That is 47 people per square mile of land.
What is the county seat of Kay County?
The county seat of Kay County is Newkirk.
What cities and towns are in Kay County?
Kay County has 7 incorporated places. The most populous five are Ponca City city, Blackwell city, Tonkawa city, Newkirk city, and Kaw City city; 7,431 residents live outside any incorporated place.
Is Kay County part of a metropolitan area?
Yes. It is a central county of the Ponca City, OK Micropolitan Statistical Area.
How many ZIP codes are in Kay County?
10 ZIP Code Tabulation Areas have land in Kay County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Kay County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.1 times as much land.
How many acres of land are in Kay County?
The land measurement converts to approximately 588,550 acres. Including water, total area is approximately 604,747 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.