Acres to Square Kilometers
Convert acres (ac) to square kilometers (km²). Both measure surface measurement, and the conversion comes up in real estate, farming, construction work.
The Formula
``
square kilometers = acres × 0.0040468564224
acres = square kilometers × 247.105381467
`
One acre is 0.004047 square kilometers, and one square kilometer is 247.1054 acres.
Conversion Table
| Acres | Square Kilometers |
|---|---|
| 1 ac | 0.004047 km² |
| 2 ac | 0.008094 km² |
| 5 ac | 0.020234 km² |
| 10 ac | 0.040469 km² |
| 25 ac | 0.101171 km² |
| 50 ac | 0.202343 km² |
| 100 ac | 0.404686 km² |
| 500 ac | 2.0234 km² |
| 1,000 ac | 4.0469 km² |
The Other Direction
| Square Kilometers | Acres |
|---|---|
| 1 km² | 247.1054 ac |
| 2 km² | 494.2108 ac |
| 5 km² | 1,235.53 ac |
| 10 km² | 2,471.05 ac |
| 25 km² | 6,177.63 ac |
| 50 km² | 12,355.27 ac |
| 100 km² | 24,710.54 ac |
| 500 km² | 123,552.69 ac |
| 1,000 km² | 247,105.38 ac |
What Each Unit Is
Acres (ac) — exactly 4,046.8564224 square metres, or one furlong by one chain. The area a yoke of oxen could plough in a day — long and thin, because turning wasted time.
Square Kilometers (km²) — one million square metres. The metric unit for regions, cities and land cover.
A Sense of Scale
An American football field is 1.32 acres- A soccer pitch is about 1.8 acres
- Central Park is 3.4 km²
- Manhattan is 59 km²
- Greater London is 1,572 km²
Precision
The factor 0.0040468564224 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
In Code
`javascript
const acreToSquareKilometer = (value) => value * 0.0040468564224;
``
Where This Conversion Comes Up
- Real estate
- Farming
- Construction
- Landscaping
- Flooring
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 ac with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 ac becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0 | 0 | 100.0000% |
| 3 | 0.004 | 0.548 | 1.1578% |
| 4 | 0.004 | 0.548 | 1.1578% |
The right number of significant figures is set by your input, not by the converter. If you measured acres to three significant figures, the answer in square kilometers is only good to three — writing more digits claims precision the measurement never had.