Cun (unit)

**1 cun** =
SI units
33.3×10^⁻³ m	33.33 mm
US customary units (Imperial units)
0.1094 ft	1.312 in

**1 tsun** =
SI units
37.148×10^⁻³ m	37.1475 mm
US customary units (Imperial units)
0.121875 ft	1.46250 in

**1 sun** =
SI units
30.3×10^⁻³ m	30.30 mm
US customary units (Imperial units)
99.4×10^⁻³ ft	1.193 in

Cun

Chinese name

Chinese

寸

Transcriptions
Standard Mandarin
Hanyu Pinyin	cùn
Wade–Giles	ts'un
Yue: Cantonese
Jyutping	tsun
Yale Romanization	chyun3
Southern Min
Hokkien POJ	chhùn

Korean name

Hangul

촌,치

Hanja

寸

Transcriptions
Revised Romanization	chon
McCune–Reischauer	ch'on

Japanese name

Kanji

寸

Hiragana

すん

Transcriptions
Romanization	sun

The cun (Chinese: 寸; pinyin: cùn; Wade–Giles: ts'un; Japanese: sun; Korean: chon) is a traditional Chinese unit of length. Its traditional measure is the width of a person's thumb at the knuckle, whereas the width of the two forefingers denotes 1.5 cun and the width of all fingers side-by-side is three cuns. In this sense it continues to be used to chart acupuncture points on the human body in various uses of traditional Chinese medicine.

The cun was part of a larger system, and represented one-tenth of a chi ("Chinese foot"). In time the lengths were standardized, although to different values in different jurisdictions. (See chi (unit) for details.)

In Hong Kong, using the traditional standard, it measures ~3.715 cm (~1.463 in) and is called a "tsun".^[1] In the twentieth century in the Republic of China, the lengths were standardized to fit with the metric system, and in current usage in People's Republic of China and Taiwan it measures 3 ¹⁄₃ cm (~1.312 in).