Area Converter
Square units, acres and hectares.
1 acre = 0.004046856422 km². Enter any value to convert acres (ac) to square kilometers (km²), or use the table below for common values.
km² = ac × 0.004046856422
Example: 10 ac = 0.04046856422 km². To convert the other way, use ac = km² × 247.1053815.
Quick mental estimate: multiply by about 0.004.
| Acres (ac) | Square Kilometers (km²) |
|---|---|
| 1 ac | 0.004046856422 km² |
| 2 ac | 0.008093712845 km² |
| 3 ac | 0.01214056927 km² |
| 4 ac | 0.01618742569 km² |
| 5 ac | 0.02023428211 km² |
| 6 ac | 0.02428113853 km² |
| 7 ac | 0.02832799496 km² |
| 8 ac | 0.03237485138 km² |
| 9 ac | 0.0364217078 km² |
| 10 ac | 0.04046856422 km² |
| 15 ac | 0.06070284634 km² |
| 20 ac | 0.08093712845 km² |
| 25 ac | 0.1011714106 km² |
| 30 ac | 0.1214056927 km² |
| 40 ac | 0.1618742569 km² |
| 50 ac | 0.2023428211 km² |
| 75 ac | 0.3035142317 km² |
| 100 ac | 0.4046856422 km² |
| 250 ac | 1.011714106 km² |
| 500 ac | 2.023428211 km² |
| 1,000 ac | 4.046856422 km² |
The acre is 43,560 square feet (about 4,047 m²), the traditional unit for farmland and building plots in the US and UK.
The square kilometer equals one million square meters, used for the areas of cities, countries and lakes.
Use the formula km² = ac × 0.004046856422. For example, 10 ac = 0.04046856422 km².
1 ac = 0.004046856422 km².
Use ac = km² × 247.1053815. 1 km² = 247.1053815 ac.