To convert square millimeters to square kilometers, multiply the value by 1 × 10⁻¹². To go the other way, multiply square kilometers by 1,000,000,000,000 to get square millimeters.
| Square Millimeters (mm²) | Square Kilometers (km²) |
|---|---|
| 1 mm² | 1 × 10⁻¹² km² |
| 2 mm² | 2 × 10⁻¹² km² |
| 5 mm² | 5 × 10⁻¹² km² |
| 10 mm² | 1 × 10⁻¹¹ km² |
| 20 mm² | 2 × 10⁻¹¹ km² |
| 50 mm² | 5 × 10⁻¹¹ km² |
| 100 mm² | 1 × 10⁻¹⁰ km² |
| 500 mm² | 5 × 10⁻¹⁰ km² |
| 1,000 mm² | 1 × 10⁻⁹ km² |
25 mm² × 1 × 10⁻¹² = 2.5 × 10⁻¹¹ km²
Try this example →250 mm² × 1 × 10⁻¹² = 2.5 × 10⁻¹⁰ km²
Try this example →Square millimeter (mm²). A square millimeter is the area of a square with 1 mm sides, used for small parts, wire and pipe cross-sections.
Square kilometer (km²). A square kilometer is one million square meters (100 hectares), used for countries, cities and lakes.
There are 1 × 10⁻¹² square kilometers in one square millimeter.
Multiply the number of square millimeters by 1 × 10⁻¹². For example, 10 square millimeters equal 1 × 10⁻¹¹ square kilometers.
One square kilometer equals 1,000,000,000,000 square millimeters.