Convert Square Mile to Square Kilometer (mi² → km²)

Converting square miles to square kilometers is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in square miles

   Start with the number of square miles (mi²) you want to convert.
2. 2
   Multiply by 2.589988

   The conversion factor from mi² to km² is 2.589988. Multiply your value by this number.
3. 3
   Read the result in square kilometers

   The result is your value in square kilometers (km²).

Multiply the value in square miles by 2.589988. For the reverse direction, multiply by 0.386102.

• ✓1 mi² = 2.59 km² = 640 acres.
• ✓US land survey "section" = 1 mi²; "township" = 36 mi².
• ✓Common in US geography; replaced by km² in most of world.

• ✗Confusing square miles with statute miles (length).
• ✗Using 2.5 km² shortcut — correct 2.59 km² differs by 3.5%.
• ✗Mixing nautical square miles (irregular) with statute square miles.

What is the Square Mile?

The square mile equals exactly 2.589988110336 square kilometers (or 640 acres) and is the American unit for measuring large geographic areas: counties, states, watersheds, and large parks. The continental United States covers about 3 million square miles, and Texas alone is 268,597 mi². Population density in US contexts is given in people per square mile (e.g., New York City has about 27,000 people/mi²). The square mile relates to the acre (640 acres = 1 mi²), the square kilometer (1 mi² ≈ 2.59 km²), the square foot (1 mi² = 27,878,400 ft²), and the hectare (1 mi² ≈ 259 ha). It is the natural large-area unit for American geographic discussion, though metric countries use square kilometers for the same purpose.

• US states, counties and cities
• UK geographic and historical boundaries
• Large estate and national-park reporting in Anglo contexts

What is the Square Kilometer?

The square kilometer equals 1,000,000 square meters (or 100 hectares) and is the international standard for measuring large areas: cities, national parks, lakes, watersheds, and country-level statistics. Population density is conventionally given in people per km² (e.g., Singapore has roughly 8,400 people/km², Mongolia has fewer than 2). The largest US national park, Wrangell-St. Elias in Alaska, covers about 53,000 km². France is 643,801 km², and the largest country, Russia, spans 17 million km². The square kilometer relates to the square meter (1 km² = 1,000,000 m²), the hectare (1 km² = 100 ha), the square mile (1 km² ≈ 0.386 mi²), and the acre (1 km² ≈ 247.1 acres). Geographic information systems, climate science, and regional planning all rely on square kilometers as the base unit for area.

• Country and city geographic area reporting
• National-park and protected-area sizes
• Large-scale environmental studies (deforestation, etc.)