Square Kilometers to Acres
Convert square kilometers (km²) to acres (ac). Both measure surface measurement, and the conversion comes up in real estate, farming, construction work.
The Formula
``
acres = square kilometers × 247.105381467
square kilometers = acres × 0.0040468564224
`
One square kilometer is 247.1054 acres, and one acre is 0.004047 square kilometers.
Conversion Table
| 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 |
The Other Direction
| 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 |
What Each Unit Is
Square Kilometers (km²) — one million square metres. The metric unit for regions, cities and land cover.
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.
A Sense of Scale
Central Park is 3.4 km²- Manhattan is 59 km²
- Greater London is 1,572 km²
- An American football field is 1.32 acres
- A soccer pitch is about 1.8 acres
Precision
The factor 247.105381467 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 squareKilometerToAcre = (value) => value * 247.105381467;
``
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 km² with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 km² becomes | Error |
|---|---|---|---|
| 0 | 247 | 33,839 | 0.0426% |
| 1 | 247.1 | 33,852.7 | 0.0022% |
| 2 | 247.11 | 33,854.07 | 0.0019% |
| 3 | 247.105 | 33,853.39 | 0.0002% |
| 4 | 247.1054 | 33,853.44 | — |
The right number of significant figures is set by your input, not by the converter. If you measured square kilometers to three significant figures, the answer in acres is only good to three — writing more digits claims precision the measurement never had.