How to measure Japanese sword size properly
* The nagasa is the most important specification of a sword (blade). This is considered the blade length, despite it's not the full length of the sword. The nagasa is measured in a straight line from the mune-machi (back of the blade which sits inside the habaki) to the tip of the kissaki (point).
* The nakago is measured from the mune-machi to the tip of the nakago (nakago-jiri).
* The kissaki (point) is measured from the yokote to the tip of the kissaki. Sori (curvature)(see below) is measured from the back of the blade (mune) at the widest point on a straight line from the mune-machi to the tip of the kissaki (point).
Most katana are hand-made and the measurements vary from sword to sword. Traditionally, Japanese swords are measured in shaku, sun and bu. 1 shaku is commonly approximated to be 12 inches (1 foot).