Square Kilometer to Square Mile Converter
Area · unit-converter
Convert Square Kilometer to Square Mile with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations use square-meter-based definitions (international feet / yard standards, acre, hectare, and regional units like pyeong/tsubo).
Calculator
From: Square Kilometer (km2)
To: Square Mile (mi2)
About Square Kilometer
The square kilometer is a metric unit equal to one million square meters. It is standard for city sizes, large properties, and regional planning in metric countries.
About Square Mile
The square mile is an imperial and US customary unit of area equal to the area of a square one statute mile on a side. It is common for large land parcels and geography in the US and UK.
How to convert square kilometers to square miles
1 square kilometer is equal to 0.38610215854245 square mile:
1 km2 = (1000000 m² ÷ 2589988.110336 m²) mi2 = 0.38610215854245 mi2
Each square kilometer is defined as 1000000 m² and each square mile as 2589988.110336 m², so one km2 equals 1000000 ÷ 2589988.110336 mi2 = 0.38610215854245 mi2.
Let a(km2) be the numeric value of the same area measured in Square Kilometer (km2), and a(mi2) the value in Square Mile (mi2). Then:
a(mi2) = a(km2) × (1000000 / 2589988.110336)
Equivalently, divide by how many km2 fit into one mi2 (m² per mi2 divided by m² per km2):
a(mi2) = a(km2) ÷ 2.589988110336
Or: square mile = square kilometer ÷ 2.589988110336
Examples
Example #1: Convert 20 km2 to square mile
20 km2 = 20 km2 × (1000000/2589988.110336) mi2 = 7.7220431709 mi2
20 km2 = 20 km2 ÷ 2.589988110336 = 7.7220431709 mi2
Example #2: Convert 50 km2 to square mile
50 km2 = 50 km2 × (1000000/2589988.110336) mi2 = 19.3051079271 mi2
50 km2 = 50 km2 ÷ 2.589988110336 = 19.3051079271 mi2
Summary
To convert Square Kilometer to Square Mile, multiply the value in km2 by the ratio of square meters per km2 divided by square meters per mi2. Equivalently: value_mi2 = value_km2 × (1000000 / 2589988.110336). Numerically, 1 km2 equals 0.38610215854244584 mi2.
Relationship context
You are converting between metric (SI) (Square Kilometers) and US customary / imperial (Square Miles). Metric area is decimal from the square meter; US/imperial units use feet, yards, miles, and acres tied to international feet (0.3048 m) and related definitions. The numeric factor used here is 3.861022e-1.
Conversion tables
| Square Kilometer (km2) | Square Mile (mi2) |
|---|---|
| 0.1 | 0.0386102159 |
| 1 | 0.3861021585 |
| 2 | 0.7722043171 |
| 3 | 1.1583064756 |
| 4 | 1.5444086342 |
| 5 | 1.9305107927 |
| 6 | 2.3166129513 |
| 7 | 2.7027151098 |
| 8 | 3.0888172683 |
| 9 | 3.4749194269 |
| Square Kilometer (km2) | Square Mile (mi2) |
|---|---|
| 10 | 3.8610215854 |
| 20 | 7.7220431709 |
| 30 | 11.5830647563 |
| 40 | 15.4440863417 |
| 50 | 19.3051079271 |
| 60 | 23.1661295125 |
| 70 | 27.027151098 |
| 80 | 30.8881726834 |
| 90 | 34.7491942688 |
| 100 | 38.6102158542 |