As an experienced Iaido trainer, I get a lot of students in my class who come into the program with katana swords that aren’t right for them. Since Iaido is the art of removing the katana from the scabbard (saya), striking, and then returning the sword to the saya, all in one fluid and controlled motion, the length of the blade is important.

I’ll even admit that my first katana was too big for me, resulting in an accidental cut to my left hand. Nothing too serious, thankfully, but it changed my perspective from having a katana that looks good to one that actually fit its intended purpose for the training I was enrolled in.

When working with a 26″+ sharp blade, safety is my primary focus, therefore I changed my registration process to inform incoming students of sizing calculations before class begins.

How does having a sword that is too long affect safety?

Not having the proper length katana can cause difficulties in controlling blade thrusts, as well as false depth perception. What I mean by ‘false depth perception’ is that if the blade is too long it’s easy to underestimate the range you’ll have during training. If the actual blade length reaches further than you think it will, you can easily injure yourself or others training with you.

How to size the sheet

There are numerous methods of sizing, and depending on which sensei you speak to, each may suggest a different sizing method. There are two considerations to keep in mind when sizing a katana; the length of the handle (tsuka) and the length of the blade.

one.) To size the tsuka, place your arm at your side with your forearm forward so that your elbow forms a 90 degree angle. Now use a tape measure to measure the length from the elbow to the base of the wrist. This is roughly how long your tsuka should be. If your tsuka is too long, it can interfere with your movement and get caught in your side, causing the blade to slip.

2.) To measure leaf length, the method I have found works best and suggest my students follow is a leaf height to length chart (one can be seen below in the resources section). ). If you are 5′ 2″ tall your blade length should be 27.5″ and for every 2″ in height add a half inch to the blade length.

If you’re still not sure what length to get, you can always start your Iaido training with a Bokken, a wooden training sword. I actually recommend this as it allows you to become familiar with the art without risking hurting yourself or those around you.

Now keep in mind that these sizing methods are simply my method of sizing my students and you should consult your sensei for proper length before purchasing a katana.

Iaido is a beautiful martial art and the katana is a great weapon that comes from the ancient Japanese tradition. I advise all readers to use their best judgment and use a katana at their own risk.