Use this useful tool to convert area choosing one of the 21 units of measurment included in this app, that are:
square meter, square kilometer, square hectometer, square decameter, square decimeter, square centimeter and square millimeter
Ares and derivates:
hectare, are and centiare
square mile, acre, rood, square yard, square foot and square inch
Modern Chinese units:
lí, fen, mu, shí and qing
For every units of measurment are also included formulas to convert that unit as you want.