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Square Miles to Square Kilometers Converter

1 square mile = 2.58998811 km². Enter any value to convert square miles (mi²) to square kilometers (km²), or use the table below for common values.

Results

1 mi² =2.58998811 km²square miles → square kilometers
1 mi²2.58998811 km²
1 km²0.3861021585 mi²
Formula
km² = mi² × 2.58998811
1 mi² in other units
UnitValue
square meters (m²)2,589,988.11
square kilometers (km²)2.58998811
square inches (in²)4,014,489,600
square feet (ft²)27,878,400
square yards (yd²)3,097,600
acres (ac)640
hectares (ha)258.998811

Formula

km² = mi² × 2.58998811

Example: 10 mi² = 25.8998811 km². To convert the other way, use mi² = km² × 0.3861021585.

Quick mental estimate: multiply by about 2.6.

Square Miles to Square Kilometers conversion table

Square Miles (mi²)Square Kilometers (km²)
1 mi²2.58998811 km²
2 mi²5.179976221 km²
3 mi²7.769964331 km²
4 mi²10.35995244 km²
5 mi²12.94994055 km²
6 mi²15.53992866 km²
7 mi²18.12991677 km²
8 mi²20.71990488 km²
9 mi²23.30989299 km²
10 mi²25.8998811 km²
15 mi²38.84982166 km²
20 mi²51.79976221 km²
25 mi²64.74970276 km²
30 mi²77.69964331 km²
40 mi²103.5995244 km²
50 mi²129.4994055 km²
75 mi²194.2491083 km²
100 mi²258.998811 km²
250 mi²647.4970276 km²
500 mi²1,294.994055 km²
1,000 mi²2,589.98811 km²

About square miles and square kilometers

The square mile is 640 acres, used for large land areas such as counties and national parks in the US.

The square kilometer equals one million square meters, used for the areas of cities, countries and lakes.

Other Area conversions

Square Kilometers → Square MilesReverse conversionSquare Meters → Square Kilometersm² → km²Square Inches → Square Kilometersin² → km²Square Feet → Square Kilometersft² → km²Square Yards → Square Kilometersyd² → km²Square Miles → Square Metersmi² → m²Square Miles → Square Inchesmi² → in²Square Miles → Square Feetmi² → ft²Square Miles → Square Yardsmi² → yd²Square Miles → Acresmi² → acSquare Miles → Hectaresmi² → haAcres → Square Kilometersac → km²Hectares → Square Kilometersha → km²

Frequently asked questions

How do I convert square miles to square kilometers?

Use the formula km² = mi² × 2.58998811. For example, 10 mi² = 25.8998811 km².

What is 1 square mile in square kilometers?

1 mi² = 2.58998811 km².

How do I convert square kilometers back to square miles?

Use mi² = km² × 0.3861021585. 1 km² = 0.3861021585 mi².