Convert Square Centimeters to Square Kilometres (cm2 to km2)
1 square centimeter (cm²) = 1 × 10⁻¹⁰ square kilometres (km²). 1 km² = 10000000000 cm². Example: 15 cm² = 15 × 1 × 10⁻¹⁰ = 1.5 × 10⁻⁹ km².
Also searched as square centimeters to km2, square centimeters in km2, square centimeters into square kilometres, cm2 to km2, cm2 in square kilometres, cm2 into square kilometre, square centimeter to square kilometre, cm2 to square kilometres converter, square centimeters to square kilometers and how many square kilometres in a square centimeter.
1 cm² = 1e-10 km²
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk square centimeter to square kilometre converter to paste a column from Excel.
How to Convert Square Centimeter to Square Kilometre
- 1 cm² = 1 × 10⁻¹⁰ km²
- 1 km² = 10000000000 cm²
- Example: convert 15 cm² to km²: 15 cm² = 15 × 1 × 10⁻¹⁰ km² = 1.5 × 10⁻⁹ km²
Formula
km² = cm² ÷ 10000000000
Derivation from SI units:
- 1 cm² = (0.01 m)² = 10⁻⁴ m²
- 1 km² = (1000 m)² = 10⁶ m² = 100 ha
- 1 cm² = 0.0001 m² ÷ 1000000 m² per km² = 1 × 10⁻¹⁰ km²
Both units are defined exactly, so the factor is exact. Square Centimeter definition: square centimeter; Square Kilometre definition: square kilometre.
Worked examples
- A reading of 20 cm² converts to 2 × 10⁻⁹ km².
20 cm² × 1 × 10⁻¹⁰ = 2 × 10⁻⁹ km² - A value of 200 cm² is 2 × 10⁻⁸ km².
200 cm² × 1 × 10⁻¹⁰ = 2 × 10⁻⁸ km²
Square Centimeter to Square Kilometre conversion table
| Square Centimeters (cm²) | Square Kilometres (km²) |
|---|---|
| 1 cm² | 1 × 10⁻¹⁰ km² |
| 2 cm² | 2 × 10⁻¹⁰ km² |
| 5 cm² | 5 × 10⁻¹⁰ km² |
| 6.45 cm² | 6.45 × 10⁻¹⁰ km² |
| 10 cm² | 1 × 10⁻⁹ km² |
| 20 cm² | 2 × 10⁻⁹ km² |
| 25 cm² | 2.5 × 10⁻⁹ km² |
| 38.3 cm² | 3.83 × 10⁻⁹ km² |
| 50 cm² | 5 × 10⁻⁹ km² |
| 100 cm² | 1 × 10⁻⁸ km² |
| 200 cm² | 2 × 10⁻⁸ km² |
| 500 cm² | 5 × 10⁻⁸ km² |
| 929 cm² | 9.29 × 10⁻⁸ km² |
| 1000 cm² | 1 × 10⁻⁷ km² |
| 10000 cm² | 0.000001 km² |
Where it's used
Square Centimeters are used for test areas in air-permeability testing (ISO 9237: 5, 10, 20, 50, 100 cm²; ASTM D737: 38.3 cm²), while square kilometres appear in city, lake and country areas. Both measure area, so the conversion is a fixed factor.
Square Centimeter to other area units
| Conversion | 1 cm² equals |
|---|---|
| square centimeter to square kilometre | 1 × 10⁻¹⁰ km² |
| square centimeter to square meter | 0.0001 m² |
| square centimeter to square foot | 0.001076391042 ft² |
| square centimeter to square inch | 0.15500031 in² |
| square centimeter to hectare | 1 × 10⁻⁸ ha |
| square centimeter to acre | 2.471053815 × 10⁻⁸ ac |
| square centimeter to square millimeter | 100 mm² |
| square centimeter to square yard | 0.0001195990046 yd² |
Show 1 more units
| square centimeter to square mile | 3.861021585 × 10⁻¹¹ mi² |
|---|
Frequently asked questions
How many square kilometres are in 1 square centimeter?
1 cm² = 1 × 10⁻¹⁰ km².
How do I convert square centimeters to square kilometres?
Multiply the value in cm² by 1 × 10⁻¹⁰, or divide it by 10000000000. For example, 15 cm² × 1 × 10⁻¹⁰ = 1.5 × 10⁻⁹ km².
Is the cm² to km² conversion exact?
Yes. Both units are defined exactly, and 1 cm² is exactly 1 × 10⁻¹⁰ km².
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2 with SI prefix centi.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Square Centimeters to Square Kilometres (cm2 to km2). Retrieved October 25, 2026, from https://scientificconverters.com/area/square-centimeters-to-square-kilometers/
IEEE
Scientific Converters, "Convert Square Centimeters to Square Kilometres (cm2 to km2)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/area/square-centimeters-to-square-kilometers/