历代尺度，皆本诸黄钟而损益不同。有以黄钟之长，均作九寸，而寸皆九分，此黄帝命
伶伦始造律之尺也，是名古律尺，又名纵黍尺。选中式之 黍，一黍之纵长，命为一分，九
分为一寸，九寸共八十一分，是为一尺。有以黄钟之长，均作十寸，而寸皆十分者，此舜同
律度量衡之尺，至夏后氏而未尝改，故名夏尺。传曰夏禹十寸为尺，盖指此尺也，又名古度
尺，又名横黍尺。选择中式之 黍，一黍之横广，命为一分，十分为一寸，十寸共计百分，是为
一尺。有以黄钟之长，均作四段，加出一段而为尺者，此商尺也。适当夏尺十二寸五分，传
曰成汤十二寸为尺，盖指此尺也。有以黄钟之长，均作五段，减去一段而为尺者，此周尺
也。适当夏尺八寸，传曰武王八寸为尺，盖指此尺也。有以黄钟之长，均作九寸，外加一寸
为尺，此汉尺也。唐尺即成汤尺，而唐人用之，故又名唐尺。宋尺即黄帝尺，而宋人用之，
故又名宋尺。上七代，尺共五种。纵黍之尺，黄帝尺也，宋尺也；横黍之尺，夏尺也；斜黍之
尺，汉尺也。互相考证，皆有补于律者。
蔡元定曰∶周家十寸、八寸皆为尺。以十寸之尺起度，则十尺为丈，十丈为引；以八寸
之尺起度，则八尺为寻，倍寻为常。说文曰∶十寸为尺，八寸为咫。然则尺之与咫，二器之
名也。今人但知八寸为咫，乃别是一物之名而非尺也。
礼记王制曰∶古者以周尺八尺为步，今以周尺六尺四寸为步。（礼记王制，撰自汉文时。郑世子
曰∶今以周尺，周字当作夏字。陈祥道曰∶六尺四寸者，十寸之尺也。十寸尺之六尺四寸，乃八寸尺
之八尺也。）小尔雅广度篇曰∶跬，一举足也，倍跬谓之步。（跬音傀。）司马法曰∶六尺为步。
郑世子曰∶按唐虞及夏后氏之制步也，皆以夏尺六尺为步。商以夏尺一尺二寸五分为
尺，故以五尺为步。周以夏尺八寸为尺，故以八尺为步。（置一尺二寸五分为实，五因，得六尺二寸五
分。置八寸为实，八因，得六尺四寸。然则商之一步，乃夏尺六尺二寸五分；周之一步，乃夏尺六
尺四寸也。）今工部收藏宝源局所铸量地铜尺，五尺为步。今之五尺，乃夏尺之六尺四寸，周之八尺也。以夏
尺八寸均作十寸，即周尺也，周尺最小。以夏尺一尺二寸五分均作十寸，即商尺也，商尺最
大，即今木匠所用曲尺也。盖自鲁班家传以至于唐，唐人谓之大尺，由唐至今用之，名曰今
尺，又名营造尺，盖此尺即殷汤尺也。去二寸，即夏禹之尺。夏禹之尺去二寸，即周武王之
尺。是今一曲尺，包括三代之制，不待累黍而自明矣。且夫黄帝至于舜禹，历世因仍，未尝
损益；惟殷周始改统易朔，而损益之道兴焉。故又因此以知黄帝针经孔穴，舜同律度量衡，
皆与夏尺同，而禹之身为度者，亦因夏尺而可想见也。
又曰∶岐伯云八尺之士，与周礼云人长八尺相符，则是上自黄帝，下至成周，数千年间，
人与尺度，未尝有异，此盖言魁伟丈夫之身，非众人之度也，故黄帝问于伯高曰众人之度长
七尺五寸是也，外台亦作七尺五寸，正与此同。梁陶弘景撰本草序录，一用累黍之法，孙思
邈从而用之，其书言尺则用夏家古尺，而又参诸司马法六尺为步以互证之，其立意之精，岂
寻常医家者所及？但孙氏云夏尺古尺，即江淮吴越所用八寸小尺是也，当唐尺八寸。唐会
要云∶唐高祖武德四年，行开元通宝钱，径八分，盖唐尺之八分也。夫一钱径八分，十钱径
八寸，即孙氏所谓夏家古尺之一尺也。开元钱今固有之，以钱考尺，则尺可知矣。近世医
家，取同身寸法，其说一出，无复考古，幸孙氏之方及唐会要可证耳。众人身度，当以黍尺
七尺五寸为准，其如曹交之长，九尺为有余，晏子之短，六尺为不足，二者折衷之，亦得七尺
五寸，故孔子荀子，皆谓七尺之体为中人之率，黍尺七尺五寸，盖今曲尺六尺也。素问、周
礼所谓八尺者，黍尺八尺，比今曲尺六尺四寸也，其伟人之度欤？故素有八尺及七尺五寸
二说。而庸俗弗晓古今尺度不同，乃谓古今人品有异，岂不谬哉？！
历代使用的尺度，都以黄钟律管的长度为基础，但具体的增减有所不同。有一种是以黄钟的长度平均分为九寸，每一寸为九分，这是黄帝命令伶伦最初制定的律尺，称为古律尺，又叫做纵黍尺。选取颗粒饱满的黍米，一粒黍米的纵向长度定为一分，九分为一寸，九寸共八十一分，这就是一尺。有一种是以黄钟的长度平均分为十寸，每一寸为十分，这是舜帝统一律、度、量、衡时使用的尺，到了夏朝也没有改变，所以称为夏尺。传说中说夏禹以十寸为一尺，大概指的就是这种尺，又称为古度尺，或者横黍尺。选取颗粒饱满的黍米，一粒黍米的横向宽度定为一分，十分为一寸，十寸共计一百分，这就是一尺。有一种是以黄钟的长度平均分为四段，再加出一段作为一尺，这是商代的尺。它相当于夏尺的一尺二寸五分，传说中说成汤（商汤）以十二寸为一尺，大概指的就是这种尺。有一种是以黄钟的长度平均分为五段，减去一段作为一尺，这是周代的尺。它相当于夏尺的八寸，传说中说武王以八寸为一尺，大概指的就是这种尺。有一种是以黄钟的长度平均分为九寸，另外再加上一寸作为一尺，这是汉代的尺。唐尺就是成汤尺，唐人使用它，所以又称唐尺。宋尺就是黄帝尺，宋人使用它，所以又称宋尺。上述七个朝代，尺共有五种类型。纵黍之尺，包括黄帝尺和宋尺；横黍之尺，即夏尺；斜黍之尺，即汉尺。互相考证，都对研究音律有所补益。
蔡元定说：周代既有十寸为一尺，也有八寸为一尺。用十寸的尺来度量，则十尺为一丈，十丈为一引；用八寸的尺来度量，则八尺为一寻，两寻（十六尺）为一常。《说文解字》说：十寸为尺，八寸为咫。那么尺和咫，是两种器物的名称。现在的人只知道八寸为咫，以为那是另一种东西的名称，而不是尺。
《礼记·王制》说：古代用周尺八尺为一步，现在用周尺六尺四寸为一步。（《礼记·王制》撰写于汉文帝时期。郑世子说：现在的“周尺”，“周”字应当作“夏”字。陈祥道说：六尺四寸，是指十寸为一尺的尺。十寸尺的六尺四寸，相当于八寸尺的八尺。）《小尔雅·广度篇》说：跬，迈出一只脚；两倍跬称为步。（跬音傀。）《司马法》说：六尺为一步。郑世子说：考察唐尧、虞舜及夏朝的制度，都是以夏尺六尺为一步。商代用夏尺的一尺二寸五分作为一尺，所以以五尺为一步。周代用夏尺的八寸作为一尺，所以以八尺为一步。（将一尺二寸五分作为基数，乘以五，得到六尺二寸五分。将八寸作为基数，乘以八，得到六尺四寸。那么商代的一步，相当于夏尺的六尺二寸五分；周代的一步，相当于夏尺的六尺四寸。）现在工部收藏的宝源局所铸造的量地铜尺，以五尺为一步。现在的五尺，相当于夏尺的六尺四寸，也就是周尺的八尺。如果把夏尺的八寸平均分为十寸，就是周尺，周尺最小。如果把夏尺的一尺二寸五分平均分为十寸，就是商尺，商尺最大，也就是现在木匠所用的曲尺。从鲁班家传一直到唐代，唐人称之为大尺，从唐代至今沿用，名为今尺，又名营造尺，这个尺其实就是殷商汤王的尺。去掉两寸，就是夏禹的尺。夏禹的尺去掉两寸，就是周武王的尺。所以现在的一个曲尺，包含了夏、商、周三代的制度，不需要累积黍米来验证就能明白。况且从黄帝到舜、禹，历代沿袭，未曾增减；只有殷、周开始改变正统和历法朔日，增减之道才兴起。因此由此可以知道，黄帝的《针经》中的孔穴位置，舜帝统一律度量衡，都与夏尺相同，而禹以身体的尺寸作为标准，也可以根据夏尺推想出来。
又说：岐伯说的“八尺之士”，与《周礼》中说的“人身长八尺”相符，这说明从上自黄帝，下至成周，几千年来，人的身高和尺度没有差异，这大概是说高大魁梧的男子的身高，并非普通人的标准。所以黄帝问伯高说普通人的身高是七尺五寸，这正是如此，《外台秘要》也写作七尺五寸，正与此相同。梁朝的陶弘景撰写《本草序录》，完全采用累黍的方法，孙思邈也沿用了这种方法。他的书中说尺时用夏代古尺，并参考《司马法》中“六尺为步”的说法互相印证，其立意之精妙，岂是一般庸医所能达到的？但是孙思邈说夏尺古尺，就是江淮吴越地区所使用的八寸小尺，相当于唐尺的八寸。《唐会要》记载：唐高祖武德四年，发行开元通宝钱，直径八分，这大概是唐尺的八分。一枚钱的直径是八分，十枚钱排起来的直径是八寸，这就是孙氏所说的夏家古尺的一尺。开元钱现在确实还有存世，用钱来考证尺，那么尺的大小就可以知道了。近代医家采用同身寸法，这种说法一出，就不再考究古代制度，幸好孙思邈的方书及《唐会要》可以作证。普通人的身高，应当以黍尺七尺五寸为标准。像曹交那样高的，九尺算是有余；晏子那样矮的，六尺算是不足，取这两者的折中，也是七尺五寸。所以孔子、荀子都说七尺的身体是中人的标准。黍尺七尺五寸，相当于现在的曲尺六尺。《素问》、《周礼》所说的八尺，是黍尺八尺，相当于现在的曲尺六尺四寸，这大概是伟人的尺寸吧？所以《素问》中有八尺和七尺五寸两种说法。而平庸世俗之人不懂古今尺度不同，竟然说古今人的体质有差异，这难道不是荒谬吗？！
The measuring standards of all dynasties were based on the length of the Huangzhong (Yellow Bell, a standard pitch pipe used for calibration) but varied in their specific divisions. One method divided the length of the Huangzhong into nine cun (Chinese inches), with each cun consisting of nine fen (Chinese lines). This was the chi (ruler) initially created by Ling Lun under the command of the Yellow Emperor (Huangdi), known as the Ancient Law Chi or the Vertical Millet Chi. By selecting well-formed millet grains, the longitudinal length of one grain was defined as one fen; nine fen made one cun, and nine cun (totaling eighty-one fen) constituted one chi. Another method divided the length of the Huangzhong into ten cun, with each cun consisting of ten fen. This was the chi used when Shun unified the laws, measures, and weights, and it remained unchanged during the Xia Dynasty, hence named the Xia Chi. Legends state that Yu of Xia used ten cun per chi, referring to this ruler, also called the Ancient Degree Chi or Horizontal Millet Chi. By selecting well-formed millet grains, the transverse width of one grain was defined as one fen; ten fen made one cun, and ten cun (totaling one hundred fen) constituted one chi. A third method divided the length of the Huangzhong into four segments and added one extra segment to form a chi; this was the Shang Chi. It corresponded to 1.25 chi of the Xia Chi. Legends state that Tang Cheng (King Tang of Shang) used twelve cun per chi, referring to this ruler. A fourth method divided the length of the Huangzhong into five segments and subtracted one segment to form a chi; this was the Zhou Chi. It corresponded to eight cun of the Xia Chi. Legends state that King Wu of Zhou used eight cun per chi, referring to this ruler. A fifth method divided the length of the Huangzhong into nine cun and added one extra cun to form a chi; this was the Han Chi. The Tang Chi was identical to the Tang Cheng Chi but used by the Tang people, hence also called the Tang Chi. The Song Chi was identical to the Huangdi Chi but used by the Song people, hence also called the Song Chi. Among the aforementioned seven dynasties, there were five types of chi. The Vertical Millet Chi included the Huangdi Chi and the Song Chi; the Horizontal Millet Chi was the Xia Chi; the Diagonal Millet Chi was the Han Chi. Mutual verification among these provided supplements to the study of musical laws.
Cai Yuanding stated: In the Zhou Dynasty, both ten-cun and eight-cun rulers were used as chi. Using the ten-cun chi for measurement, ten chi made one zhang (Chinese foot), and ten zhang made one yin. Using the eight-cun chi for measurement, eight chi made one xun, and two xun (sixteen chi) made one chang. The *Shuowen Jiezi* states: "Ten cun is a chi, eight cun is a zhi." Thus, chi and zhi are names of two different instruments. Modern people only know that eight cun is a zhi, considering it the name of a separate object rather than a type of chi.
The *Book of Rites: Wang Zhi* states: "In ancient times, a step was eight chi using the Zhou Chi; now, a step is six chi and four cun using the Zhou Chi." (The *Wang Zhi* chapter was compiled during the reign of Emperor Wen of Han. Zheng Shizi noted: The term "Zhou Chi" here should likely be read as "Xia Chi." Chen Xiangdao explained: Six chi and four cun refers to the ten-cun chi. Six chi and four cun of the ten-cun chi is equivalent to eight chi of the eight-cun chi.) The *Xiao Erya: Guang Du Pian* states: "Kui is the distance covered by one step; double Kui is called Bu (step)." (*Kui* sounds like 'kui'). The *Sima Fa* states: "Six chi make one Bu." Zheng Shizi commented: Examining the systems of Yao, Shun, and the Xia Dynasty, a step was consistently six chi of the Xia Chi. The Shang Dynasty used 1.25 chi of the Xia Chi as its own chi, so it defined a step as five chi. The Zhou Dynasty used eight cun of the Xia Chi as its own chi, so it defined a step as eight chi. (Calculating with 1.25 chi as the base, multiplied by five, yields 6.25 chi of the Xia Chi. Calculating with eight cun as the base, multiplied by eight, yields 6.4 chi of the Xia Chi. Therefore, one step in the Shang Dynasty equaled 6.25 chi of the Xia Chi; one step in the Zhou Dynasty equaled 6.4 chi of the Xia Chi.) Currently, the copper rulers cast by the Baoyuan Bureau and kept by the Ministry of Works define five chi as one step. These current five chi are equivalent to 6.4 chi of the Xia Chi, or eight chi of the Zhou Chi. If the eight cun of the Xia Chi are evenly divided into ten cun, it becomes the Zhou Chi, which is the smallest. If the 1.25 chi of the Xia Chi are evenly divided into ten cun, it becomes the Shang Chi, which is the largest, and corresponds to the carpenter's square ruler used today. Passed down from Lu Ban through generations until the Tang Dynasty, where it was called the Large Chi, and continued to be used until now as the Jin Chi or Yingzao Chi, this ruler is essentially the Chi of King Tang of Yin. Removing two cun from it yields the Chi of Yu of Xia. Removing two cun from the Chi of Yu of Xia yields the Chi of King Wu of Zhou. Thus, a single carpenter's square ruler encompasses the systems of the Three Dynasties, making it self-evident without needing to count millet grains. Furthermore, from the Yellow Emperor to Shun and Yu, the systems were inherited without alteration; only with the Yin and Zhou dynasties did changes in orthodoxy and calendar start occur, leading to the introduction of adjustments in measurements. Therefore, we can infer that the acupoints in the *Huangdi Neijing Lingshu* (Yellow Emperor's Classic of Acupuncture), the unification of laws and measures by Shun, and the bodily proportions of Yu were all consistent with the Xia Chi.
It is further stated: Qibo's mention of an "eight-chi tall man" aligns with the *Rites of Zhou*'s statement that "human height is eight chi." This indicates that from the Yellow Emperor down to the late Zhou period, spanning thousands of years, human stature and measurement standards remained unchanged. This likely referred to the height of exceptionally tall men, not the average person. Hence, the Yellow Emperor asked Bo Gao about the average height, which was seven chi and five cun. This is corroborated by the *Waitai Miyao*, which also records seven chi and five cun. Tao Hongjing of the Liang Dynasty, in his preface to the *Bencao*, exclusively used the millet-counting method. Sun Simiao followed suit, using the Ancient Xia Chi in his texts and cross-referencing it with the *Sima Fa*'s definition of "six chi as one step." His meticulous approach far exceeded that of ordinary physicians. However, Sun Simiao claimed that the Ancient Xia Chi was the small eight-cun ruler used in Jianghuai, Wu, and Yue regions, equivalent to eight cun of the Tang Chi. The *Tang Huiyao* records: "In the fourth year of Wude (621 AD) under Emperor Gaozu of Tang, Kaiyuan Tongbao coins were issued, with a diameter of eight fen, corresponding to eight fen of the Tang Chi." If one coin has a diameter of eight fen, ten coins lined up have a diameter of eight cun, which constitutes one chi of the Ancient Xia Chi mentioned by Sun. Kaiyuan Tongbao coins still exist today; thus, by examining the coins, the size of the chi can be determined. In recent times, physicians adopted the "same-body inch" method, abandoning archaeological research. Fortunately, Sun Simiao's prescriptions and the *Tang Huiyao* provide evidence. The standard height for ordinary people should be based on seven chi and five cun of the millet chi. Cao Jiao, being very tall at nine chi, was above average; Yan Zi, being short at six chi, was below average. Taking the average of these two extremes yields seven chi and five cun. Therefore, Confucius and Xunzi stated that a body of seven chi represents the average person. Seven chi and five cun of the millet chi is equivalent to six chi of the current carpenter's square ruler. The "eight chi" mentioned in the *Suwen* and *Rites of Zhou* refers to eight chi of the millet chi, which equals 6.4 chi of the current carpenter's square ruler, representing the stature of giants. Thus, the *Suwen* contains two theories: eight chi and seven chi five cun. Vulgar people, ignorant of the differences between ancient and modern scales, absurdly claim that human constitutions differ between ancient and modern times.