As an experienced Iaido trainer, I receive many students in my class who enter the program with katana swords that aren’t the correct fit for them. Since Iaido is the art of removing the katana from the sheath (saya), striking, and then replacing the sword in the saya all in a fluid controlled motion, blade length is important.
I’ll even admit that my first katana was much too large for me resulting in an accidental cut to my left hand. Luckily nothing too serious but it did change my outlook from having a katana that looks nice to one that actually fits the purpose intended for the training I was enrolled in.
When working with a sharp 26″+ blade, safety is a primary focus of mine therefore I’ve changed my enrollment process to inform incoming students of the sizing calculations before starting class.
How does having a sword too long effect safety?
Not having the proper length katana can cause difficulty in the control of the blade thrusts as well as false depth perceptions. What I mean by ‘false depth perception’ is that if the blade is too long it becomes easy for one to underestimate the reach it will have while in training. If your actual blade length reaches farther than what you perceive it will reach you can easily harm yourself or others participating in the training with you.
How to size the blade
There are numerous methods for sizing and depending on the sensei you talk to each may suggest a different sizing method. There are two considerations to make when sizing a katana; the handle (tsuka) length and the blade length.
1.) To size the tsuka place your arm to your side with your forearm straight ahead so that your elbow makes a 90 degree angle. Now use a tape measure to measure the length from your elbow to the base of your wrist. This is roughly how long your tsuka should be. If you’re tsuka is too long it can interfere with your motion and get caught on your side causing the blade to slip.
2.) For measuring blade length the method I have found to work best and suggest my students to follow is a height to blade length ratio 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 unsure about what length to get you can always start off Iaido training with a Bokken, a wooden training sword. I actually recommend this since it allows you to familiarize yourself with the art without doing so at the risk of injuring yourself or others around you.
Now keep in mind that these sizing methods are merely my method for sizing my students and you should consult your sensei on the appropriate length before purchasing a katana.
Iaido is beautiful martial art and the katana is a great weapon stemming from ancient Japanese tradition. I advise all readers to use good judgment and use a katana at your own risk.
How to Size Yourself for a Katana