1 Square Mile equals 2.58999 Square Kilometers.
| Square Mile (mi²) | Square Kilometer (km²) |
|---|---|
| 0.001 mi² | 0.00258999 km² |
| 0.01 mi² | 0.0258999 km² |
| 0.1 mi² | 0.258999 km² |
| 1 mi² | 2.58999 km² |
| 2 mi² | 5.17998 km² |
| 5 mi² | 12.9499 km² |
| 10 mi² | 25.8999 km² |
| 25 mi² | 64.7497 km² |
| 50 mi² | 129.499 km² |
| 100 mi² | 258.999 km² |
| 500 mi² | 1,294.99 km² |
| 1,000 mi² | 2,589.99 km² |
To convert Square Miles to Square Kilometers, multiply the value by 2.58999. This factor comes from the ratio of the two units' definitions: one Square Mile equals 2.58999 Square Kilometers.
For example: 1 Square Mile = 2.58999 Square Kilometers, and 10 Square Miles = 25.8999 Square Kilometers.
To convert in the reverse direction — from Square Kilometers to Square Miles — multiply by 0.386102.
The square mile (mi²) is the area of a square with sides one mile long, equal to 640 acres or approximately 2.59 square kilometers. It is the standard unit for large geographic areas in the United States — county sizes, metropolitan areas, national parks, and state areas are all routinely expressed in square miles. Rhode Island, the smallest US state, covers about 1,034 mi²; Alaska, the largest, covers about 663,268 mi².
The square mile underlies the US land survey system. A "section" is exactly one square mile, 36 sections form a "township," and these units governed the orderly subdivision of American land from the Land Ordinance of 1785 onward. If you've looked at an aerial map of the US Midwest and noticed the perfectly regular grid of roads and farm fields, you're seeing sections and townships at work — a coordinate system laid out in square miles across millions of acres.
Population density figures for US cities and regions are commonly expressed in people per square mile. New York City has about 28,000 people per square mile (one of the densest in the US); Los Angeles has about 8,000; and Montana has about 7 per square mile. These figures illustrate the unit's usefulness for communicating the character of place. The square mile also appears in discussions of urban sprawl, fire perimeters, and military operation areas — contexts where scale is meaningful and the unit is familiar to the American audience.
The square kilometer (km²) is the standard metric unit for measuring large geographic areas: the size of countries, cities, lakes, forests, and islands. One square kilometer equals 100 hectares or 1,000,000 square meters. For comparison: Vatican City covers about 0.44 km²; Manhattan island is about 87 km²; the city of London covers about 1,572 km²; and France, one of Europe's larger countries, covers about 551,695 km².
Population density is almost universally expressed as people per square kilometer in international statistics, allowing meaningful comparison across countries. Bangladesh, one of the world's most densely populated countries, has about 1,100 people/km²; Canada, one of the least dense, has about 4 people/km². Urban planners use square kilometers for city boundary definitions, transportation corridor assessments, and land use mapping.
In environmental science, deforestation rates, habitat loss, and wildfire extents are all measured in square kilometers. The annual loss of Amazon forest runs to tens of thousands of square kilometers. Sea ice extent in the Arctic is tracked in millions of square kilometers — in September 2012, the record minimum Arctic sea ice extent was about 3.41 million km². The square kilometer thus makes large-scale environmental change legible in a way that square meters or hectares would not.
1 Square Mile equals 2.58999 Square Kilometers.
To convert Square Miles to Square Kilometers, multiply by 2.58999. For example, 1 Square Mile = 2.58999 Square Kilometers.
1 Square Kilometer equals 0.386102 Square Miles.