How to Convert Ares to Square kilometres (a 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 ares into square kilometres by hand, with examples and a quick-reference table.
The conversion
To convert ares to square kilometres, multiply the value by 0.0001. To go the other way, divide by the same number (or multiply by 10,000). Because the factor is tiny, scientific notation keeps the numbers manageable.
Square kilometres = ares × 0.0001
Worked examples
- 3 a = 0.0003 km²
- 12.5 a = 0.00125 km²
- 75 a = 0.0075 km²
Ares to Square kilometres table
| Ares | Square kilometres |
|---|---|
| 1 a | 0.0001 km² |
| 2 a | 0.0002 km² |
| 5 a | 0.0005 km² |
| 10 a | 0.001 km² |
| 20 a | 0.002 km² |
| 25 a | 0.0025 km² |
| 50 a | 0.005 km² |
| 100 a | 0.01 km² |
| 250 a | 0.025 km² |
| 500 a | 0.05 km² |
| 1,000 a | 0.1 km² |
Common questions
Is a 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 Ares converter.
Mistakes to avoid
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
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.
Background
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.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
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.
For any value, use the Ares to Square kilometres Converter or browse all area converters.
Run your own numbers: Ares to Square kilometres Converter