How to convert square miles to square kilometers
To convert a measurement in square miles to square kilometers, multiply the value by 2.589988. The conversion factor comes from the relationship between both units and the square meter.
For example, to convert 5 mi² to square kilometers: 5 × 2.589988 = 12.949941 km².
What is a square mile?
A square mile is an imperial and US customary unit of area equal to the area of a square one mile on each side, or 640 acres, about 2.59 square kilometers. The square mile is the traditional unit for large land areas in the US and UK. In the US Public Land Survey System, a 'section' is exactly one square mile, the building block of the township grid.
Common uses of square miles include: Areas of US and UK cities and counties; Land survey sections (640 acres); Geographic and census area reporting; Property and ranch land in imperial countries.
What is a square kilometer?
A square kilometer is a metric unit of area equal to the area of a square one kilometer on each side, or 1,000,000 square meters. The square kilometer became the standard unit for large land areas as the metric system spread. It is used for the areas of cities, countries, lakes, and other geographic features worldwide.
Common uses of square kilometers include: Areas of cities, countries, and regions; Land, forest, and agricultural coverage; Lake and reservoir surface area; Population density (people per km²).
Square Miles to square kilometers worked examples
Here are some common values converted:
1 mi² = 2.589988 km² 5 mi² = 12.949941 km² 10 mi² = 25.899881 km² 50 mi² = 129.499406 km² 100 mi² = 258.998811 km²
Frequently asked questions
How many square kilometers are in one square mile?
One square mile (mi²) equals 2.589988 square kilometers (km²). Multiply any value in square miles by 2.589988 to convert to square kilometers.
How do I convert square miles to square kilometers?
Multiply the value in square miles by 2.589988. For example, 5 mi² × 2.589988 = 12.949941 km².
How do I convert square kilometers to square miles?
Multiply the value in square kilometers by 0.386102158542, or divide by 2.589988. Use the swap button on the converter above to reverse the direction.
Is the square mile to square kilometer conversion exact?
Yes. Area conversions derive from the exact 1959 international definitions of the meter, yard, and foot, so the factors are exact.
What is the formula for square miles to square kilometers?
The formula is: km² = mi² × 2.589988. This comes from the definition of both units relative to the square meter.