County outline
Where Blackford County is located
Area breakdown
Land accounts for 99.7% of Blackford County’s measured area and water for 0.3%. Its combined area converts to 428.9 square kilometers or approximately 105,973 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 165.082 | 427.56 | 105,652.5 |
| Water | 0.501 | 1.298 | 320.6 |
| Total | 165.583 | 428.858 | 105,973.1 |
How Blackford County compares
By original Census land area, Blackford County ranks #89 of 92 in Indiana and #3045 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.416 times the Indiana county-equivalent median of 396.4 square miles. It accounts for 0.5% of the combined county land area in the state.
See the complete Indiana ranking · What counts as a county equivalent?
Population and density of Blackford County
The Census Bureau estimates that 11,730 people lived in Blackford County on July 1, 2025. That ranks #2,374 of 3,222 county equivalents nationally and #85 of 92 in Indiana. Since the April 1, 2020 estimates base of 12,110, the population has declined by 380 (−3.1%), compared with +2.8% for Indiana as a whole.
With 165.1 square miles of land, that is 71 people per square mile (27 per km²), placing Blackford County #1,246 nationally for density and #58 in Indiana. The median county equivalent has 47 people per square mile; the Indiana median is 88. Put another way, there are about 9 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 12,108 | 12,047 | 11,902 | 11,881 | 11,822 | 11,730 |
| Change | — | −61 | −145 | −21 | −59 | −92 |
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 Blackford County
4 incorporated places lie at least partly in Blackford County. Together they are home to 7,730 people (65.9%); the other 4,000 (34.1%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Hartford City city, with 5,898 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Hartford City cityCounty seat | 5,898 | −3% | 3.882 |
| Montpelier city | 1,489 | −3.1% | 1.497 |
| Shamrock Lakes town | 215 | −3.2% | 0.263 |
| Dunkirk cityAlso in 1 other county | 128 | −4.5% | 1.175 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Blackford County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Blackford 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
7 ZIP Code Tabulation Areas have land in Blackford County; 2 of them have most of their land inside the county, and the others mainly cover neighboring areas.
46952469894733647338473484735947369
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 Blackford County
Blackford County shares a land border with 4 county equivalents. Each of them has more land than Blackford County. The largest neighbor is Grant County (414.1 mi²) and the smallest is Wells County (368.1 mi²). Together with its neighbors, Blackford County forms a block of 1,723.3 mi² of land, of which it holds 9.6%.
| Bordering county equivalent | Land mi² | Size vs. Blackford | Compare |
|---|---|---|---|
| Grant County | 414.1 | 2.5× larger | Compare |
| Delaware County | 392.1 | 2.4× larger | Compare |
| Jay County | 383.9 | 2.3× larger | Compare |
| Wells County | 368.1 | 2.2× larger | Compare |
How big is Blackford County compared with U.S. states?
Blackford County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 6.3 times as much. Indiana’s county land could hold about 217 areas the size of Blackford County.
Another way to picture it: the same land area would fill a square about 12.8 miles (20.7 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 Blackford County?
Blackford County has more land than 177 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 Blackford County at #3,067 nationally by total area, 22 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 0.3%, compared with a national county-equivalent median of 1.2% — 0.9 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 Blackford County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #3044 | Lake County, Tennessee | 165.8 | Compare |
| #3045 | Blackford County, Indiana | 165.1 | This county |
| #3046 | Pickett County, Tennessee | 163 | 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 40.472672, -85.323730. 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: 427,559,411 m²; AWATER: 1,298,757 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 Blackford County?
Blackford County, Indiana has 165.1 square miles (427.6 km²) of land and 0.501 square miles of water, for a total area of 165.6 square miles. It ranks #3045 of 3,222 U.S. county equivalents by land area.
Is Blackford County the largest county in Indiana?
No. Blackford County ranks #89 of 92 in Indiana by land area. The largest is Allen County, with 657.1 square miles of land.
What counties border Blackford County?
Blackford County shares a land border with Jay County, Grant County, Wells County, and Delaware County.
What is the population of Blackford County?
The Census Bureau estimates Blackford County had 11,730 residents on July 1, 2025, ranking #2,374 of 3,222 county equivalents. That is 71 people per square mile of land.
What is the county seat of Blackford County?
The county seat of Blackford County is Hartford City.
What cities and towns are in Blackford County?
Blackford County has 4 incorporated places. The most populous are Hartford City city, Montpelier city, Shamrock Lakes town, and Dunkirk city; 4,000 residents live outside any incorporated place.
Is Blackford County part of a metropolitan area?
No. Blackford County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Blackford County?
7 ZIP Code Tabulation Areas have land in Blackford County, and 2 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Blackford County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 6.3 times as much land.
How many acres of land are in Blackford County?
The land measurement converts to approximately 105,652 acres. Including water, total area is approximately 105,973 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.