Shaku

Shaku is a term with multiple uses in East Asia, most notably as a traditional unit of length in Japan. The unit is written with the kanji 尺 and read as shaku in Japanese (and chi in Chinese). It forms part of the historic East Asian measurement system and is still encountered in traditional contexts.

In measurement terms, one shaku equals 10 sun and is about 30.3 centimeters (0.303 meters). It is used in carpentry, architecture, and textile sizing. Traditional architectural scales often express lengths in shaku, with related units such as the ken, which equals six shaku (about 1.818 meters). Japan formally adopted the metric system in the 20th century, but shaku remains familiar in crafts and historical references.

Shaku also appears as a Japanese surname. Notable bearers include Soen Shaku, a Zen master who played a key role in introducing Zen to the United States in the late 19th century.

The character 尺 simply denotes a unit of length and can mean “ruler” or “foot” in certain East Asian contexts. The exact length of shaku has varied historically and regionally, but the modern standard is defined as approximately 30.3 cm.