Use this useful tool to convert area choosing one of the 21 units of measurment included in this app, that are:

Metric acceleration:
square meter, square kilometer, square hectometer, square decameter, square decimeter, square centimeter and square millimeter

Ares and derivates:
hectare, are and centiare

Imperial units:
square mile, acre, rood, square yard, square foot and square inch

Modern Chinese units:
lí, fen, mu, shí and qing