[1] It continues to be used to chart acupuncture points on the human body, and, in various uses for traditional Chinese medicine.
A cun was made up of 10 fen, which depending on the period approximated lengths or widths of millet grains,[2] and represented one-tenth of a chi ("Chinese foot").
In Hong Kong, using the traditional standard, it measures ~3.715 cm (~1.463 in) and is written "tsun".
[4] 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[citation needed] it measures 3+1/3 cm (~1.312 in).
In Japan, the corresponding unit, sun (寸), was standardized at 1000⁄33 mm (3.03 cm, ~1.193 in, or ~0.09942 ft).