Nagasa: The Blade Length of the Katana

The nagasa describes the length of the katana blade.

Measuring the nagasa:

The measurement starts from the back of the habaki and runs to the tip of the blade in a straight line. As with many measurements, tradition uses the shaku (30.3 cm / 11.9 in). The blade of a katana must be at least 2 shaku, that is, more than 60 cm (23.6 in).

It is essential to take this measurement from the mune-machi and not from the tsuba, as some sellers do. The two give different measurements and therefore also change the balance point.

Below you will find a chart to help you choose the size of your blade according to your own height.

Height (cm)	Length (shaku)	Length (cm)
155 (61.0 in)	1.95-2.10	58-63 (22.8-24.8 in)
158 (62.2 in)	2.00-2.15	60-66 (23.6-26.0 in)
161 (63.4 in)	2.00-2.20	60-66 (23.6-26.0 in)
164 (64.6 in)	2.05-2.25	60-68 (23.6-26.8 in)
167 (65.7 in)	2.10-2.25	63.5-68 (25.0-26.8 in)
170 (66.9 in)	2.10-2.30	63.5-68 (25.0-26.8 in)
173 (68.1 in)	2.15-2.35	66-71 (26.0-28.0 in)
175 (68.9 in)	2.15-2.35	66-71 (26.0-28.0 in)
177 (69.7 in)	2.20-2.40	66-73 (26.0-28.7 in)
180 (70.9 in)	2.25-2.45	68-73 (26.8-28.7 in)
180-182 (70.9-71.7 in)	2.25-2.50	68-76 (26.8-29.9 in)
182 (71.7 in)	2.30-2.50	68-76 (26.8-29.9 in)
185 (72.8 in)	2.35-2.55	71-76 (28.0-29.9 in)
187 (73.6 in)	2.35-2.60	71-78 (28.0-30.7 in)
190 (74.8 in)	2.40-2.60	73-78 (28.7-30.7 in)
193 (76.0 in)	2.45-2.65	73-81 (28.7-31.9 in)
195 (76.8 in)	2.45-2.70	73-81 (28.7-31.9 in)
198 (78.0 in)	2.50-2.70	76-81 (29.9-31.9 in)

The choice of blade length is related more to practice, such as iaido, for example.

The nagasa and its impact on the performance of the katana

The length of the nagasa directly influences the performance characteristics of the katana. A longer blade offers greater reach and power, which can be an advantage when cutting. A shorter blade, on the other hand, allows better handling and more control. Choosing the right nagasa therefore depends on the preferences and needs of each practitioner.

The nagasa and the different forging schools

Over the centuries, Japanese smiths developed various forging schools and styles, each with its own characteristics in terms of nagasa and blade proportions. Forging schools such as Yamashiro, Bizen and Soshu produced katanas with distinctive nagasa lengths, which reflect the preferences and requirements of the samurai of their time. The length of the nagasa can therefore help to identify the forging school of a particular katana and to learn more about its history.

The nagasa and historical regulations

Throughout Japanese history, regulations were introduced to control the length of katana blades. For example, during the Edo period (1603-1868), the Tokugawa government imposed restrictions on the length of katanas to limit their use and carrying by samurai and civilians. These regulations influenced trends in nagasa length and helped shape the evolution of the katana over the centuries.

The nagasa and the needs of modern practitioners

Today, practitioners of martial arts such as kendo, iaido and battojutsu have specific needs in terms of nagasa. The ideal dimensions depend on the discipline practised, the level of skill and the build of the individual. Many katana makers offer made-to-measure blades to meet the requirements of modern practitioners and ensure the best experience when using the sword.

Tips for choosing the right nagasa

To choose the nagasa that suits you best, take into account your height, your physical strength and your level of experience. Beginners may prefer a shorter blade for easier handling and control, while more experienced practitioners may opt for a longer blade to benefit from greater reach and power. Do not hesitate to consult instructors or martial arts experts for personalised advice on the nagasa best suited to your needs.