Convert square miles to square kilometers

1 mi²=2.58999km²

Use the converter below to change any square miles value into square kilometers instantly — with formula, conversion table, and real-world examples.

You have

Equals

2.589988

Conversion formula

Forward

square kilometers = square miles × 2.58999

Reverse

square miles = square kilometers × 0.3861

Example: 10 mi² × 2.58999 = 25.8999 km².

About both units

From

Square Mile

mi²

The square mile equals 2.589988 square kilometres. It is used for US and UK geographic areas — city, county, state and country sizes. Greater London is 607 mi²; the US state of Texas is 268,597 mi².

Real-world: New York City is 302.6 mi². Texas is 268,597 mi². Greater London is 607 mi².

Read full square mile reference →

Square Kilometer

km²

The square kilometre equals 1,000,000 m² or 100 hectares. It is used for city, region and country areas. Greater London is about 1572 km². The smallest sovereign countries (Monaco, Vatican City) are under 3 km² each.

Real-world: Greater London is 1572 km². France is 643,801 km². The Serengeti National Park is 14,763 km².

Read full square kilometer reference →

Square Mile to Square Kilometer conversion table

Common square miles to square kilometers values for quick reference.

Square Mile (mi²)	Square Kilometer (km²)
1 mi²	2.58999 km²
5 mi²	12.9499 km²
10 mi²	25.8999 km²
50 mi²	129.499 km²
100 mi²	258.999 km²
500 mi²	1,294.99 km²
1,000 mi²	2,589.99 km²
5,000 mi²	12,949.94 km²
10,000 mi²	25,899.88 km²
50,000 mi²	129,499.41 km²

Tips & common mistakes

Quick tips

1 mi² = 2.59 km² = 640 acres.
US land survey "section" = 1 mi²; "township" = 36 mi².
Common in US geography; replaced by km² in most of world.

Avoid these

Confusing square miles with statute miles (length).
Using 2.5 km² shortcut — correct 2.59 km² differs by 3.5%.
Mixing nautical square miles (irregular) with statute square miles.

Frequently asked questions

How many square kilometers in a square mile?

One square mile equals 2.58999 square kilometers.

How do I convert square miles to square kilometers?

Multiply the square mile value by 2.58999 to get the equivalent in square kilometers.

What is 100 square miles in square kilometers?

100 square miles equals 258.999 square kilometers.

Is a square mile bigger than a square kilometer?

Yes. 1 square mile equals 2.58999 square kilometers, so one square mile is larger.

How to convert square miles to square kilometers without a calculator?

Multiply by 2.59 for a quick estimate; use a calculator for precise results.

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