# Unit Converter: Area (Square meter, Square foot)

• Convert area units such as Metric system, United States customary units / Imperial units, and Japanese units of measurement to each other.
• Round to the 14th decimal place.

### Metric system

 square millimeter mm2 square centimeter cm2 square meter m2 are a hectare ha square kilometre km2

### United States customary units / Imperial units

 square inch sq.in.
 square foot sq.ft. square yard sq.yd. rood ro acre ac square mile sq.mi.

### Japanese units of measurement

 shaku 勺 gō 合 tsubo 坪 se 畝 tan 反 chō 町
 jō 畳／帖
* About the notation of "e": Numbers with many digits may be displayed as "1e9". This is a computer exponential notation, where “e” represents a power of 10.
1e3 = 103 = 1,000
1e6 = 106 = 1,000,000
1e9 = 109 = 1,000,000,000
1e-3 = 10-3 = 0.001
1e-6 = 10-6 = 0.000001
1e-9 = 10-9 = 0.000000001

## Area conversion formula

### Metric system

$1 km^2 = 10^2 ha = 10^4 a = 10^6 m^2$ $1 m^2 = 10^4 cm^2 = 10^6 mm^2$

### United States customary units / Imperial units

$1 sq \ mi = 640 ac$ $1 ac = 4 ro = 4840 sq \ yd$ $1 sq \ yd = 9 sq \ ft$ $1 sq \ ft = 144 sq \ in = 929.0304 cm^2$ $1 sq \ in = 645.16 mm^2$

### Japanese units of measurement

$1\text{町} = 10\text{反} = 100\text{畝} = 3000\text{坪}$ $1\text{坪} = {\dfrac {400}{121}} m^2 \approx 3.305785 m^2$ $1\text{坪} = 10\text{合} = 100\text{勺}$ $1\text{畳／帖} = 1.62 m^2 \ (*)$

* 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.