Square Miles to Square Kilometers
One square mile is 2.59 square kilometers. This mi² to km² page has the formula, a conversion table, three worked examples and answers to common questions.
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The mi² to km² formula
One square mile corresponds to 2.58998811 square kilometers here. That single figure is the whole conversion: take the number of square miles, multiply by 2.58998811, and the product is the number of square kilometers.
If an amount is already in square kilometers, divide it by 2.58998811 to get square miles; one square kilometer is 0.38610216 square miles.
Common square miles-to-square kilometers values
Each of the 12 rows pairs an amount in square miles with its equivalent in square kilometers. Scale up or down by powers of ten, since the ratio 2.58998811 does not change.
| Square miles (mi²) | Square kilometers (km²) |
|---|---|
| 0.25 | 0.64749703 |
| 1 | 2.58998811 |
| 1.5 | 3.884982166 |
| 3 | 7.769964331 |
| 6 | 15.53992866 |
| 8 | 20.71990488 |
| 15 | 38.84982166 |
| 40 | 103.5995244 |
| 75 | 194.2491083 |
| 150 | 388.4982166 |
| 400 | 1,035.995244 |
| 2,000 | 5,179.976221 |
The converter formats numbers the same way, which means the km² column above is what you would see after typing the mi² value into the widget.
Step by step: mi² to km²
Example 1. Start with 12 mi². Multiply 12 by 2.58998811 and the converter shows 31.07985732 km².
Take 1.5 square miles as the second case. The widget returns 3.884982166 square kilometers, and that figure divided by 2.58998811 returns to about 1.5.
Working backwards, an amount of 240 km² corresponds to 92.66451805 mi².
Reverse direction (km² to mi²)
If the amount you have is in square kilometers, go to Square Kilometers to Square Miles. Here 1 km² = 0.38610216 mi², and the layout mirrors this page.
Any other pairing is available in the Area Converter, built on the same conversion function as this page.
Related conversions
Related pages with their own tables, examples and formulas:
Frequently asked questions
One square mile equals how many square kilometers?
Each square mile corresponds to 2.58998811 square kilometers, which means 25.8998811 square kilometers for 10 square miles and 258.998811 square kilometers for 100 square miles.
How many square miles are in one square kilometer?
1 km² = 0.38610216 mi². The reverse ratio is the reciprocal of 2.58998811, so 10 km² comes to 3.861021585 mi².
24 square miles equals how many square kilometers?
Multiply 24 by 2.58998811 and the answer is 62.15971465 km².
Will the km² figure be rounded?
Calculation uses ordinary floating-point numbers, then the display is trimmed: 10 significant digits for values from 1 to 1,000, 8 for values below 1, and up to 6 decimals above 1,000. For this pair, 0.123456789 mi² gives 0.31975162 km² and 1,234.5678 mi² gives 3,197.515923 km².
What calculation sits behind mi² to km²?
The unit table gives square miles and square kilometers each a multiplier against a common reference unit. Dividing one multiplier by the other leaves 2.58998811, which is applied to whatever number is entered.
How do I convert square kilometers back to square miles?
The page titled "Square Kilometers to Square Miles" covers it, or you can press the swap button in the widget above. For this direction multiply by 0.38610216, or equivalently divide by 2.58998811. As a check, 25 km² comes to 9.652553964 mi².
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →