Convert Jo to Square Millimeter

One jo equals 1,620,000 mm². This converter allows you to easily convert between Jo and Square Millimeter in real time.

Formula

jo × 1,620,000 = mm²

Example: 1 jo = 1,620,000 mm²

What is Jo?

The jo is a Japanese unit of area based on the size of one tatami mat, standardized at 1.62 square meters for real estate purposes by the Japan Fair Trade Council. However, actual tatami dimensions vary by region: the Kyoto-style kyoma is about 1.82 m², the Tokyo-style edoma is about 1.55 m², and the Nagoya-style chukyo-ma is about 1.66 m². In Japanese housing, room sizes are almost always described in jo (for example, "a 6-jo room" or "an 8-jo living room"). This unit provides an intuitive sense of room size that is deeply rooted in Japanese residential culture.

What is Square Millimeter?

The square millimeter is a unit of area equal to a square with sides of one millimeter, or one-millionth of a square meter. It is most commonly used in electrical engineering to specify the cross-sectional area of wire conductors (for example, "a 2.5 mm² cable"). Precision-machined parts, O-ring cross-sections, and microelectronic chip features are also measured in square millimeters. In printing, the fine details of typefaces may be analyzed at this scale.