Square Kilometers to Square Miles Converter

Multiply square kilometers by 0.3861 to get square miles. 1 km² = 0.386 mi². For example, 100 km² = 38.61 square miles. Quick estimate: divide km² by 2.6 to get approximate square miles.

Square Kilometers

km²

Square Miles

mi²

Common Conversions

Key Takeaways

1 km² = 0.3861 mi². Multiply km² by 0.386 for square miles.
1 mi² = 2.59 km². About 2.6 square kilometers per square mile.
1 km² = 100 hectares = 247.1 acres.
The US is about 9.83 million km² (3.80 million mi²).
Area conversion squares the linear factor: (1.609)² = 2.59.

How Do You Convert km² to mi²?

Multiply square kilometers by 0.386102 to get square miles. The formula is: Square Miles = Square Kilometers × 0.386102. This factor comes from squaring the linear conversion: since 1 km = 0.62137 miles, 1 km² = 0.62137² = 0.3861 mi².

Sam Okafor sometimes reviews international property listings for clients interested in large rural parcels. A ranch in Patagonia listed at 500 km² converts to 500 × 0.386 = 193 square miles. For context, that is about half the size of Los Angeles proper (469 mi²) — helpful for clients who think in American city sizes.

Country and Region Size Reference

Region	Area (km²)	Area (mi²)
Vatican City	0.44	0.17
Manhattan, NYC	59	23
Washington, D.C.	177	68
New York City (5 boroughs)	783	302
Rhode Island	4,001	1,545
Belgium	30,689	11,849
Texas	695,662	268,596
Alaska	1,723,337	665,384
India	3,287,263	1,269,219
United States	9,833,520	3,796,742
Russia	17,098,242	6,601,668

When You Need This Conversion

Geography and News

International news often reports areas in square kilometers. When a wildfire covers 500 km², American readers understand it better as 193 square miles — about the size of a medium US county. Similarly, when the Amazon loses 10,000 km² of forest per year, that is 3,861 mi² — roughly the size of Connecticut plus Rhode Island.

Real Estate and Land Management

Large-scale property deals, national parks, and conservation areas are measured in km² internationally. Yellowstone National Park covers 8,983 km² (3,469 mi²). When comparing protected areas across countries, converting between km² and mi² provides immediate context.

Urban Planning

Population density is expressed as people per km² or per mi². Tokyo has about 6,158 people/km² (15,949/mi²), while New York City has 10,194 people/km² (26,403/mi²). Converting between units helps compare cities globally — and the conversion makes clear why NYC feels denser despite Tokyo having a larger total population.

Frequently Asked Questions

How many square miles are in a square kilometer?

One square kilometer equals 0.386102 square miles. Conversely, 1 square mile equals 2.58999 square kilometers. For a quick estimate, 1 km² is roughly 0.4 square miles, or about 2.5 km² per square mile.

How do I convert square kilometers to square miles?

Multiply square kilometers by 0.386102 to get square miles. For example, 100 km² x 0.3861 = 38.61 square miles. To convert back, divide square miles by 0.3861 or multiply by 2.59.

How big is 1 square kilometer?

One square kilometer is a square measuring 1,000 meters (1 km) on each side. It equals 100 hectares, 1,000,000 square meters, or about 247 acres. For comparison, Central Park in New York is about 3.41 km².

What is the area of the United States in square kilometers?

The United States covers approximately 9,833,520 km² (3,796,742 mi²), making it the third or fourth largest country by area depending on how disputed territories are counted. Russia is the largest at 17,098,242 km².

Why is the conversion factor not simply 1.609 squared?

It is. Since 1 mile = 1.60934 km, 1 square mile = 1.60934² = 2.58999 km². Conversely, 1 km² = 1/2.58999 = 0.386102 mi². Area conversions square the linear factor because area is two-dimensional.