Yin (length)

Yin refers to a traditional Chinese unit of length. While its exact equivalent in modern measurements varies depending on context and historical period, it is generally understood to be roughly equivalent to the Western foot. The modern standard value assigned to a yin is 1/3 of a meter, or approximately 33.33 centimeters (13.12 inches).

Historically, the yin was not standardized and its length differed based on regional variations, occupational usage (e.g., tailoring, construction), and dynastic period. Variations could range from approximately 23 centimeters to over 35 centimeters. Careful consideration of the historical context is necessary when interpreting historical records using the yin.

The yin is part of a larger traditional Chinese system of measurement that also includes units such as the chi (foot), cun (inch), zhang, and li. The relationships between these units varied historically, but in the modern standard:

• 1 yin = 3 chi
• 1 chi = 10 cun

The term "yin" can also appear as a component in other compound units of measurement. Furthermore, it should be noted that "Yin" also represents one half of the concept of Yin and Yang in Chinese philosophy, and should not be confused with the unit of measurement described here.