Taiwanese units of measurement

Taiwanese units of measurement (Chinese: 臺制; pinyin: Táizhì; Pe̍h-ōe-jī: Tâi-chè; Hakka: Thòi-chṳ) are the customary and traditional units of measure used in Taiwan. The Taiwanese units formed in the 1900s when Taiwan was under Japanese rule. The system mainly refers to Japanese system. The measurement refers to the traditional size of a Japanese flooring mat called a Tatami mat (made of woven dried grass) which were positioned to completely cover the floor of traditional Japanese homes, therefore it became a convenient measurement tool as mat area was standardised hundreds of years ago. In Taiwan the measurement units were pronounced in Taiwanese Hokkien and Hakka before World War II and adopted by the Mandarin-speaking immigrants from China in 1949. Today, the Taiwanese units are used exclusively, in some cases alongside official SI units, and in other cases they have been replaced by SI.

Although the Taiwanese units have similar names to those in Chinese units of measurement and Hong Kong units of measurement, the standards are different from those used in China and Hong Kong due to them being Japanese in origin.

The Taiwanese units are not used in the Chinese territories of Kinmen and Matsu which are under control of the Taiwanese authority, as these places have never been under Japanese rule. Instead, they retain the use of Chinese units in the Republican era, which are based on metric values and still mostly the same as People's Republic of China.