Square Kilometers to Square Miles Converter
Convert square kilometers to square miles instantly. One square kilometer equals exactly 0.3861022 square miles. Type in either box to convert both ways, then use the chart, worked examples and everyday sizes below.
How to convert square kilometers to square miles
Worked example: convert 90 square kilometers to square miles. Using square miles ← square kilometers × 0.3861021585, we get 90 × 0.3861021585 = 34.749194 sq mi. To check the result, convert back: 34.749194 sq mi ÷ 0.3861021585 = 90 km².
Square kilometers to square miles chart
| Square kilometers (km²) | Square miles (sq mi) |
|---|---|
| 1 km² | 0.3861022 sq mi |
| 2 km² | 0.7722043 sq mi |
| 3 km² | 1.158306 sq mi |
| 4 km² | 1.544409 sq mi |
| 5 km² | 1.930511 sq mi |
| 6 km² | 2.316613 sq mi |
| 8 km² | 3.088817 sq mi |
| 10 km² | 3.861022 sq mi |
| 12 km² | 4.633226 sq mi |
| 15 km² | 5.791532 sq mi |
| 20 km² | 7.722043 sq mi |
| 25 km² | 9.652554 sq mi |
| 30 km² | 11.58306 sq mi |
| 40 km² | 15.44409 sq mi |
| 50 km² | 19.30511 sq mi |
| 75 km² | 28.95766 sq mi |
| 100 km² | 38.61022 sq mi |
| 150 km² | 57.91532 sq mi |
| 200 km² | 77.22043 sq mi |
| 250 km² | 96.52554 sq mi |
| 500 km² | 193.0511 sq mi |
| 1,000 km² | 386.1022 sq mi |
Square miles to square kilometers (reverse)
| Square miles (sq mi) | Square kilometers (km²) |
|---|---|
| 1 sq mi | 2.589988 km² |
| 2 sq mi | 5.179976 km² |
| 5 sq mi | 12.94994 km² |
| 10 sq mi | 25.89988 km² |
| 20 sq mi | 51.79976 km² |
| 50 sq mi | 129.4994 km² |
| 100 sq mi | 258.9988 km² |
| 250 sq mi | 647.497 km² |
| 500 sq mi | 1,294.994 km² |
| 1,000 sq mi | 2,589.988 km² |
About the square kilometer and the square mile
A square kilometer is one million square meters, or 100 hectares. It describes cities, lakes and countries; Monaco covers about 2 km².
A square mile is 640 acres. It is used for county, city and country areas in the United States and United Kingdom; Manhattan covers about 23 square miles of land.
One square mile equals 2.589988 square kilometers, which makes the square mile the larger unit of the two.
Everyday sizes in square kilometers and square miles
| Everyday example (approximate) | In square kilometers | In square miles |
|---|---|---|
| A basketball court | 0.0004366 km² | 0.00016857 sq mi |
| A soccer pitch | 0.00714 km² | 0.0027568 sq mi |
| A hectare | 0.01 km² | 0.003861 sq mi |
| Vatican City | 0.44 km² | 0.16988 sq mi |
| Central Park in New York | 3.41 km² | 1.3166 sq mi |
| Manhattan (land area) | 59.1 km² | 22.819 sq mi |
Square kilometers to square miles FAQ
How many square miles are in one square kilometer?
One square kilometer equals exactly 0.3861021585 square miles. In the other direction, one square mile equals 2.5899881 square kilometers.
How do I convert square kilometers to square miles without a calculator?
convert 90 square kilometers to square miles. Using square miles ← square kilometers × 0.3861021585, we get 90 × 0.3861021585 = 34.749194 sq mi. To check the result, convert back: 34.749194 sq mi ÷ 0.3861021585 = 90 km². For a quick estimate, round the factor to 0.39. Then 90 km² is about 35.1 sq mi, compared with the exact 34.7492 sq mi (an error of 1%). That is close enough for planning, but use the calculator above when the number matters.
What is a basketball court in square miles?
A basketball court is about 0.0004366 square kilometers, which is 0.00016857 square miles. Treat that as an approximate everyday figure rather than an official measurement.
Are the square kilometers and square miles the same in every country?
The square kilometer is exactly 1,000,000 m². The square mile is exactly 2,589,988.110336 m² and equals 640 acres.