Legal Measurement Units
1 square kilometer (km) = 100 hectares (ha) = 247.1 acres = 0.386 square miles
1 square meter (m) = 10.764 square feet (ft); 1 are = 100 square meters (m)
1 hectare (ha) = 15 mu = 1 hm² = 10,000 square meters (m) = 2.471 acres = 0.01 square kilometers (where 'hm' means hectometers, and 'hm²' means hectometer squared)
1 square mile = 2.590 square kilometers (km)
1 acre = 0.4047 hectares (ha) = 4.047 × 10 square kilometers (km) = 4047 square meters (m)
1 square foot (ft) = 0.093 square meters (m); 1 square inch (in) = 6.452 square centimeters (cm)
1 square yard (yd) = 0.8361 square meters (m)
1 mu = 2000/3 square meters ≈ 666.666 square meters
Urban Measurement Units
1 square li = 22,500 square zhang
1 square zhang = 100 square feet
1 square foot = 100 square inches
1 square inch = 100 square fen
1 square fen = 100 square li
1 square li = 100 square hao