Acres to Square Kilometers (km²) Converter
Enter a value to instantly convert between area units.
1 Acre = 0.004 Square Kilometer
Key Formulas
Acre → Square Foot
ft² = ac × 43560Square Foot → Acre
ac = ft² × 0.0000229568Hectare → Acre
ac = ha × 2.47105Acre → Hectare
ha = ac × 0.404686Formula
km² = acres × 0.00404686One acre equals 0.004047 km² — since 1 acre = 4047 m² and 1 km² = 1,000,000 m², the conversion is 4047/1,000,000 = 0.004047. International property investors and agricultural economists convert between acres and km² when comparing land values across metric and imperial markets.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A European investor converting 100 acres (0.405 km²) US farmland to km² for comparison with German holdings.
100 ac = 0.4047 km²
An agricultural analyst calculating 500 acres (0.2 km²) to km² for international crop yield database.
500 ac = 2.024 km²
A ranch broker converting 1000 acres (1.58 mi²) to km² for Australian buyer due diligence.
1000 ac = 4.047 km²
A conservation organization converting 10,000 acres (15.6 mi²) to km² for global habitat reporting.
10000 ac = 40.47 km²