Li (short)

The li in Mandarin, or lei in Cantonese, is a traditional Chinese unit of length. One li equals 10 hao, 1/10 of a fen, 1/1000 of a chi, or 1/3 mm in China.

Present law on Chinese length units

This law of length measurement was issued by the Chinese government in 1929, and has been effective since 1 January 1930. The base unit chi is defined to be 1/3 meter.

Pinyin	Character	Relative value	Metric value	Imperial value	Notes
háo	毫		μm		Chinese mil
lí	釐 or 厘		mm	0.0131 in	Chinese calibre
fēn	市分		mm	0.1312 in	Chinese line
cùn	市寸		cm	1.312 in	Chinese inch
chǐ	市尺	1	cm	13.12 in	Chinese foot
zhàng	市丈	10	m	3.645 yd	Chinese yard
yǐn	引	100	m	36.45 yd	Chinese chain
lǐ	市里	1500	500 m	546.8 yd	Chinese mile, this li is not the small li above, which has a different character and tone

These units are based on the metric system. The Chinese word for metre is 米 mǐ, which can take the Chinese standard SI prefixes. A kilometre, however, may also be called 公里 gōnglǐ, i.e. a metric lǐ.
In the engineering field, traditional units are rounded up to metric units.

Pinyin	Character	Relative value	Metric value	Imperial value	Notes
hū	忽		1 μm		Authorized name: 微米
sī	絲 or 丝		10 μm		Authorized name: 忽米
háo	毫		100 μm		Authorized name: 絲米 or 丝米
lí	釐 or 厘		1 mm		Authorized name: 毫米
fēn	公分		10 mm		Authorized name: 釐米 or 厘米
cùn	公寸		100 mm		Authorized name: 分米
chǐ	公尺	1	1 m		Authorized name: 米
Zhàng	公丈	10	10 m		Authorized name: 十米
yǐn	公引	100	100 m		Authorized name: 百米
lǐ	公里	1000	1000 m		this li is not the small li above, which has a different character and tone