Edo-Period: Conversion of the “Kujirajaku” (Whale Ruler) Used in Kimono Tailoring to Centimeters

I calculated 1 shaku = 25/66 meters. The “kujira-jaku” (whale ruler) corresponds on the carpenter’s scale (kane-jaku) to 1 shaku, 2 sun, and 5 bu, which is longer than the 1 shaku used in carpentry. Items such as the six-shaku fundoshi and three-shaku obi are measured using the “kujira-jaku.” Incidentally, bolts of fabric are counted as one “tan” per roll; this was the length required to make a full set of clothes for one person and was called a “three-jo” bolt. Since items like furisode required longer sleeves and thus more fabric, they were referred to as “four-jo” bolts.