Convert Square Miles to Square Kilometers

Enter the area in square miles below to get the value converted to square kilometers.

SWAP UNITS
Results in Square Kilometers:
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1 sq mi = 2.589988 sq km

How to Convert Square Miles to Square Kilometers

conversion scale showing square miles and equivalent square kilometers area values

To convert a square mile measurement to a square kilometer measurement, multiply the area by the conversion ratio. One square mile is equal to 2.589988 square kilometers, so use this simple formula to convert:

square kilometers = square miles × 2.589988

The area in square kilometers is equal to the square miles multiplied by 2.589988.

For example, here's how to convert 5 square miles to square kilometers using the formula above.
5 sq mi = (5 × 2.589988) = 12.949941 sq km

Square miles and square kilometers are both units used to measure area. Keep reading to learn more about each unit of measure.

Square Miles

One square mile is equal to the area of a square with sides that are 1 mile long. One square mile is roughly equal to 2.59 square kilometers.

The square mile is a US customary and imperial unit of area. Square miles can be abbreviated as sq mi, and are also sometimes abbreviated as mi². For example, 1 square mile can be written as 1 sq mi or 1 mi².

Square Kilometers

One square kilometer is equal to the area of a square with sides that are 1 kilometer in length.

The square kilometer, or square kilometre, is a multiple of the square meter, which is the SI derived unit for area. In the metric system, "kilo" is the prefix for 103. A square kilometer is sometimes also referred to as a square km. Square kilometers can be abbreviated as sq km, and are also sometimes abbreviated as km². For example, 1 square kilometer can be written as 1 sq km or 1 km².

Square Mile Measurements and Equivalent Square Kilometer Conversions

Common square mile values converted to the equivalent square kilometer value
Square Miles Square Kilometers
1 sq mi 2.59 sq km
2 sq mi 5.18 sq km
3 sq mi 7.77 sq km
4 sq mi 10.36 sq km
5 sq mi 12.95 sq km
6 sq mi 15.54 sq km
7 sq mi 18.13 sq km
8 sq mi 20.72 sq km
9 sq mi 23.31 sq km
10 sq mi 25.9 sq km
11 sq mi 28.49 sq km
12 sq mi 31.08 sq km
13 sq mi 33.67 sq km
14 sq mi 36.26 sq km
15 sq mi 38.85 sq km
16 sq mi 41.44 sq km
17 sq mi 44.03 sq km
18 sq mi 46.62 sq km
19 sq mi 49.21 sq km
20 sq mi 51.8 sq km
21 sq mi 54.39 sq km
22 sq mi 56.98 sq km
23 sq mi 59.57 sq km
24 sq mi 62.16 sq km
25 sq mi 64.75 sq km
26 sq mi 67.34 sq km
27 sq mi 69.93 sq km
28 sq mi 72.52 sq km
29 sq mi 75.11 sq km
30 sq mi 77.7 sq km
31 sq mi 80.29 sq km
32 sq mi 82.88 sq km
33 sq mi 85.47 sq km
34 sq mi 88.06 sq km
35 sq mi 90.65 sq km
36 sq mi 93.24 sq km
37 sq mi 95.83 sq km
38 sq mi 98.42 sq km
39 sq mi 101.01 sq km
40 sq mi 103.6 sq km

More Square Mile Area Conversions

US Customary
Convert to Acres
1 sq mi is equal to 640 acres
Convert to Square Yards
1 sq mi is equal to 3,097,600 square yards
Convert to Square Feet
1 sq mi is equal to 27,878,400 square feet
Convert to Square Inches
1 sq mi is equal to 4,014,489,599.5 square inches
SI Units
Convert to Square Meters
1 sq mi is equal to 2,589,988.1 square meters
Convert to Square Centimeters
1 sq mi is equal to 25,899,881,100 square centimeters
Convert to Square Millimeters
1 sq mi is equal to 2,589,988,110,000 square millimeters
Other Metric Units
Convert to Hectares
1 sq mi is equal to 258.998811 hectares
Convert to Ares
1 sq mi is equal to 25,899.9 ares