Area conversion formula
Metric system
1km2=102ha=104a=106m2
1m2=104cm2=106mm2
United States customary units / Imperial units
1sq mi=640ac
1ac=4ro=4840sq yd
1sq yd=9sq ft
1sq ft=144sq in=929.0304cm2
1sq in=645.16mm2
Japanese units of measurement
1町=10反=100畝=3000坪
1坪=121400m2≈3.305785m2
1坪=10合=100勺
1畳/帖=1.62m2 (∗)
* About tatami mats (畳 / 帖 / jō)
When written as “畳”, it is not always 1.62 m2. There are various dimensions of tatami mats such as Edo-ma and Kyo-ma. I made ”Unit Converter: Tatami”, so please use it.
When written as “帖”, it is 1.62 m2. The “畳 / 帖” written in the recent housing advertisement is 1.62 m2.