How to Convert Hectares to Square kilometres (ha 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 hectares into square kilometres by hand, with examples and a quick-reference table.
The conversion
To convert hectares to square kilometres, multiply the value by 0.01. To go the other way, divide by the same number (or multiply by 100). For a quick estimate, multiply by about 0.01.
Square kilometres = hectares × 0.01
Worked examples
- 3 ha = 0.03 km²
- 12.5 ha = 0.125 km²
- 75 ha = 0.75 km²
Hectares to Square kilometres table
| Hectares | Square kilometres |
|---|---|
| 1 ha | 0.01 km² |
| 2 ha | 0.02 km² |
| 5 ha | 0.05 km² |
| 10 ha | 0.1 km² |
| 20 ha | 0.2 km² |
| 25 ha | 0.25 km² |
| 50 ha | 0.5 km² |
| 100 ha | 1 km² |
| 250 ha | 2.5 km² |
| 500 ha | 5 km² |
| 1,000 ha | 10 km² |
Common questions
Is ha 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 Hectares 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.
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
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For any value, use the Hectares to Square kilometres Converter or browse all area converters.
Run your own numbers: Hectares to Square kilometres Converter