Legal Units of Measurement
1 square kilometre (km) = 100 hectares (hm) = 247.1 acres (acre) = 0.386 square miles (mile)
1 square metre (m) = 10.764 square feet (ft) 1 acre (are) = 100 square metres (m)
1 hectare (hm) = 15 acres = 1 hm2 = 10,000 square metres (m) = 2.471 acres (acre) = 0.01 square kilometres (where h means hundred metres, hm2 means hundred metres squared)
1 square mile = 2.590 square kilometres (km)
1 acre = 0.4047 hectare (ha) = 4.047 x 10 square kilometres (km) = 4047 square metres (m)
1 square foot (ft) = 0.093 square metres (m) 1 square inch (in) = 6.452 square centimetres (cm)
1 square yard (yd) = 0.8361 square metres (m)
1 acre = 2000/3 square metres ≈ 666.666 square metres
Municipal unit of measurement
1 square mile = 22,500 square sazhens
1 square sazhens = 100 square feet
1 square foot = 100 square inches
1 square inch = 100 square minutes
1 square minute = 100 square centimetres
1 square centimetre = 100 square millimetres