Acres to Square Kilometers Converter
1 acre ≈ 0.00404685642 square kilometers
1 acre equals 0.00404686 square kilometers
How to convert acres to square kilometers
Area factors are squared length factors: 1 ft² = (0.3048 m)². The acre here uses international feet; historic US survey acres differ slightly.
km² = ac × 0.004046856422One acre is 0.004046856422 square kilometers, so a single multiplication converts any value.
0.0404686 km² ≈ 10 × 0.004046856422Acres to square kilometers conversion table
Common values in acres, converted to square kilometers.
| Acres (ac) | Square kilometers (km²) |
|---|---|
| 1 | 0.0040468564 |
| 2 | 0.0080937128 |
| 3 | 0.012140569 |
| 4 | 0.016187426 |
| 5 | 0.020234282 |
| 10 | 0.040468564 |
| 20 | 0.080937128 |
| 25 | 0.10117141 |
| 50 | 0.20234282 |
| 100 | 0.40468564 |
| 250 | 1.0117141 |
| 500 | 2.0234282 |
| 1,000 | 4.0468564 |
About these units
acreac
Exactly 4,840 square yards, or 43,560 square feet. The customary land unit.
Reference: Derived from the international yard (1959).
square kilometerkm²
One million square metres. Used for land area and geographic regions.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.