Post #1528503

@cerement @yaodema @neauoire I was about to answer this myself, but decided to check first. Perfect answer. So I'll add that you can have similar mishaps in China with chi-cun-fen measures (often still used in tailoring). Indeed the Imperial inch is referred to in China as literally "English cun". The shaku-sun-bu measurements were almost certainly derived from older chi-cun-fen measurements, but have diverged over time. The Mainland chi today is 33+1/3cm, IIRC, to the shaku's 30.3cm.