When we make Kimonos, we use units called “shaku” and “sun” to express their size. These are Japanese traditional units and this measuring method is called “Shakkan-ho.” However, metric unit is now widely used in Japan so in most cases, artisans or makers convert the sizes measured in centimeter to shaku and sun. In fact, there are two systems for shaku and sun. When making a Kimono, we use a system called “Kujira-jaku.” Although 1 sun equals 3cm and 1 shaku equals 30cm in general, these are from another system called “Kane-jaku” which is used for architecture. In terms of Kujira-jaku, 1 sun is about 3.8cm, and 1 shaku is approximately 38cm.
As Kimonos have existed before introduction of metric units, sizes of all rolls of Kimono fabric and measurement method for people are based on Shakkan-ho. Since Shakkan-ho and metric units are indivisible each other, we still use Kujira-jaku in Kimono industry. There are some stores display Kimonos with their size using Shakkan-ho.