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

* Round to the 14th decimal place.

* 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 = 10

^{3}= 1,0001e6 = 10

^{6}= 1,000,0001e9 = 10

^{9}= 1,000,000,0001e-3 = 10

^{-3}= 0.0011e-6 = 10

^{-6}= 0.0000011e-9 = 10

^{-9}= 0.000000001日本語 / English

### 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 m^{2}. 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 m^{2}. The “畳 / 帖” written in the recent housing advertisement is 1.62 m^{2}.