how long is a katana (and how long it should be for you)

Generally speaking, the total length of a katana is 100 cm long, and the blade is about 70 cm long. This article will introduce the history behind the data, how to measure it correctly, how to find the right length for you and some fun katana in history. 

Traditionally, measuring a katana sword is called “Houryou” 法量. The term originally referred to the measurements of Buddhist statues. It is said that the reason why this term came to be used to measure the size of Japanese swords, and became established in this usage, is because katanas were once regarded as noble existences, just like gods and Buddhas.

Houryou are usually for the katana blade length (nagasa), blade curvature (sori) , blade width (Motohaba) etc, today we will focus on the katana’s total length and blade length, and understand how to choose the blade length that suits oneself best. These measurements are indispensable not only in sword making, but also when appreciating or purchasing a sword.

To begin, We should know that the unit to measure Katana sword, is Shaku (尺), in today’s unit, one shaku is  about 30cm. 1 Shaku is about a normal man’s length of his forearm from elbow to the tip. The shaku is further divided into smaller units:

1 shaku = 10 sun 寸

1 sun = 10 bu 分

1 bu = 10 rin 厘

The blade length, in Japanese is called 刃長 (Nagasa), nagasa was length of measuring a straight line from the kissaki towards the Munemachi groove at the Habaki's back. There were no official standard or regulation for the nagasa before the Edo Period. However, in the early Edo period, there was a restriction imposed that the sword length should not exceed 2 shaku 9 sun, this is called 'Edo period standard size', and the nagasa is about two shaku and three sun (about 70-73 cm). Since the average height of men in the Edo period was about 155 cm, it can be said that this was the most manageable length for samurai. And this is the most common nagasa in today as well. 

This restriction was implemented during the period known as "Shoho" (1644-1647), which was when Tokugawa Iemitsu was the reigning shogun. However, during that time, the common people hardly adhered to this restriction. Because if you are a tall person, you might find it a little short. For example the great swordsmen Miyamoto musashi, he is about 182cm tall, which considered very tall in his time, and his three beloved swords are:

Nameless (Muimei) 無銘金重: Blade length of 70 cm.

Izuminokami Fujiwara Kanesada 和泉守藤原兼重: Blade length of 81.5 cm, total length of 117.5 cm.

Ryōgai 了戒: Blade length of 85 cm. 

So don’t worry if your katana’s length is “standard” or not, because the best katana length for each person is different. your height, the length of your arms measured from fingertip to fingertip, your gender, your age, training group, and your school, these factors determine your most suitable katana length. For iaido practitioner, to help you find your best length, here is a table indicating the length of the katana corresponding to the individual's height:

There is a calculation formula to estimate the length of a sword based on height. The formula is to multiply the height by 0.43, and since this is in centimeters, it is divided by 30.3 to convert it into shaku, a traditional Japanese measurement unit. However, it is important to note that this is a general guideline, and the appropriate length and weight of a sword may vary depending on the individual's preferences and physique. It should also be considered that the length and weight of the sword may differ between males and females.

For example a 170cm tall male: 

170 x 0.43 ÷ 30.3 = 2.41 Shaku（尺）

Some interest facts:

Biggest / Longest katana in history:

The sword renowned as the world's largest Japanese sword is the "Haja-no-Ontachi"破邪の御太刀 housed in Hanaoka Hachiman Shrine in Shimotsu City, Yamaguchi Prefecture. Its blade length measures an astonishing approximately 345.5 cm, with overall length 465.5 cm and weighs a staggering 75 kg.

To put it into perspective, 345.5 cm is roughly the length of two tatami mats aligned vertically. (Note: Tatami is a traditional Japanese flooring material, and this measurement is based on the dimensions commonly used in the Kanto region.)

Indeed, the "Haja-no-Ontachi" was not wielded by samurai in actual combat. According to records passed down at Hanaoka Hachiman Shrine, the sword was dedicated by local residents during the Shikinen Sengu ceremony in 1859 (Ansei 6). This was a time of increasing external pressure from Western powers, and in the same year, the wave of the "Ansei Purge" by the shogunate was also affecting Choshu (present-day Yamaguchi Prefecture).

Given such a turbulent historical backdrop, the sword was imbued with the wish to "purge evil energy and build a peaceful society."

The master swordsmith responsible for its creation was Fujiwara Kunitsuna. He was accompanied by five apprentices and two assistants. Over one ton of sand iron was used in the production of the sword. During the quenching process, known as “clay tempered," where the heated blade is rapidly cooled with water, it is said that they dammed up a local river to carry out the work.