Area / ac → km²
Convert International acres to Square kilometers
Convert surface areas in metric and international customary units. Convert International acres (ac) to Square kilometers (km²). Find the formula, worked examples, unit definitions, and practical guidance below.
Reverse: Square kilometers to International acres →
How to convert international acres to square kilometers
Area factors are squared length factors. Acres here use international feet, not historical US survey feet.
Use x for the value in ac, b for the intermediate value in m², and y for the result in km².
km² = ac × 4046.8564224 ÷ 1000000
Worked examples
10 ac ≈ 0.040468564224 km²
Step 1: (10 × 4046.8564224) ≈ 40468.564224 m².
Step 2: 40468.564224 ÷ 1000000 ≈ 0.040468564224 km².20 ac ≈ 0.080937128448 km²
Step 1: (20 × 4046.8564224) ≈ 80937.128448 m².
Step 2: 80937.128448 ÷ 1000000 ≈ 0.080937128448 km².
Results are rounded to 12 significant digits. Converting units does not increase the precision of the original measurement. Very large or small values outside JavaScript’s finite numeric range are rejected.
About International acres
International acres (ac) measures area under the conventions above. The base value in m² is (x × 4046.8564224), where x is the numerical value in ac. Factors shown here are rounded for display; calculations use the stored factor.
About Square kilometers
Square kilometers (km²) measures area under the conventions above. The base value in m² is (x × 1000000), where x is the numerical value in km². Factors shown here are rounded for display; calculations use the stored factor.
Definitions and sources
Keep these unit conventions consistent when using measurements in construction calculations.
International acres to square kilometers reference table
| International acres (ac) | Square kilometers (km²) |
|---|---|
| 1 | 0.0040468564224 |
| 5 | 0.020234282112 |
| 10 | 0.040468564224 |
| 25 | 0.10117141056 |
| 50 | 0.20234282112 |
| 100 | 0.40468564224 |
| 1000 | 4.0468564224 |
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