Square Miles to Square Kilometers

1 square mile = 2.58998811 square kilometers. To convert square miles (mi²) to square kilometers (km²), multiply by 2.58998811.

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How to convert square miles to square kilometers

km² = mi² × 2.58998811

Example: convert 8 square miles to square kilometers.
8 mi² × 2.58998811 = 20.71990488 km²

The same relationship in reverse: 1 square kilometer = 0.3861021585 square miles, so you can also divide by 0.3861021585. Need the other direction? Use the square kilometers to square miles converter.

You will typically need this conversion for the size of cities, countries and national parks.

Square Miles to Square Kilometers conversion chart

Square Miles (mi²)Square Kilometers (km²)
1 mi²2.5899881 km²
2 mi²5.1799762 km²
3 mi²7.7699643 km²
4 mi²10.359952 km²
5 mi²12.949941 km²
6 mi²15.539929 km²
7 mi²18.129917 km²
8 mi²20.719905 km²
9 mi²23.309893 km²
10 mi²25.899881 km²
15 mi²38.849822 km²
20 mi²51.799762 km²
25 mi²64.749703 km²
30 mi²77.699643 km²
40 mi²103.59952 km²
50 mi²129.49941 km²
75 mi²194.24911 km²
100 mi²258.99881 km²
250 mi²647.49703 km²
500 mi²1,294.9941 km²
1,000 mi²2,589.9881 km²

Values rounded to 8 significant figures. The converter above shows up to 12.

About the units

Square Mile (mi²)

640 acres, about 2.59 km². Used for the area of US states, counties and cities.

Square Kilometer (km²)

One million square meters. Used for the area of cities, countries and lakes.

Frequently asked questions

How many square kilometers are in a square mile?

1 square mile = 2.58998811 square kilometers. Going the other way, 1 square kilometer = 0.3861021585 square miles.

How do I convert square miles to square kilometers?

To convert square miles to square kilometers, multiply by 2.58998811. The formula is km² = mi² × 2.58998811.

What is 8 mi² in km²?

8 square miles is 20.71990488 square kilometers (8 mi² × 2.58998811 = 20.71990488 km²).

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