How to Convert Square centimetres to Square kilometres (cm² to km²)
Area conversions are everyday maths in Singapore property: HDB flats are listed in square metres while condo listings and PSF prices use square feet. This guide shows how to convert square centimetres into square kilometres by hand, with examples and a quick-reference table.
The conversion
To convert square centimetres to square kilometres, multiply the value by 1.000000e-10. To go the other way, divide by the same number (or multiply by 1.000000e+10). Because the factor is tiny, scientific notation keeps the numbers manageable.
Square kilometres = square centimetres × 1.000000e-10
Worked examples
- 3 cm² = 3.000000e-10 km²
- 12.5 cm² = 1.250000e-9 km²
- 75 cm² = 7.500000e-9 km²
Square centimetres to Square kilometres table
| Square centimetres | Square kilometres |
|---|---|
| 1 cm² | 1.000000e-10 km² |
| 2 cm² | 2.000000e-10 km² |
| 5 cm² | 5.000000e-10 km² |
| 10 cm² | 1.000000e-9 km² |
| 20 cm² | 2.000000e-9 km² |
| 25 cm² | 2.500000e-9 km² |
| 50 cm² | 5.000000e-9 km² |
| 100 cm² | 1.000000e-8 km² |
| 250 cm² | 2.500000e-8 km² |
| 500 cm² | 5.000000e-8 km² |
| 1,000 cm² | 1.000000e-7 km² |
Common questions
Is cm² to km² exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Square kilometres to Square centimetres converter.
Mistakes to avoid
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Background
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
For any value, use the Square centimetres to Square kilometres Converter or browse all area converters.
Run your own numbers: Square centimetres to Square kilometres Converter