How to Choose & Tie an Obi

The Aikido Obi

– A Quick Guide –


For almost all Japanese martial arts the uniform is held together by a kind of belt or ‘obi,’ but if this is your first time choosing an obi or if you are looking for something new, here are a few points that will help you to find an obi that is right for you and, if need be, a few points on how to tie it.

So, to start – a small disclaimer. Everyone is different and prefers different ways of wearing their obi, so please do not take this guide as the gospel truth, but make sure to check with your sensei to make sure you are wearing your belt to the standards of your Dojo.

With that said, let us look at how to get the best length for your belt. Obi come in a few different sizes (usually from 0 to 6). Often, the length of one size will be quite uniform but please be aware that there can be differences, so it is usually best to go by the length of the belt rather than the size number. For this guide we will use the standard white Aikido belt as our frame of reference.



Size 0

Size 1

Size 2

Size 3

Size 4

Size 5

Size 6

210cm / 82.6″

220cm / 86.6”

230cm / 90.5”

250cm / 98.4”

270cm / 106.2”

290cm / 114.1”

310cm / 122.0”

With the lengths now in place let us look at how to find out which size will work best for you. As a standard we like to use the formula “Waist X 2 + 80-90cm (31”-35”).

If someone has a waist circumference of about 94cm (34”), this means that they should multiply that by two and add 80 to 90cm. This should give them a result of 268-278cm (105.5”-109.5). Therefore, a good fit would be a size 4. This size, as you can see below, gives 25-30 cm (9.8”-11.8”) of left-over belt to hang from the knot – depending on how the obi is tied.

Now of course there are different preferences for how long you want your belt. Some like the end of the belt to be almost nonexistent, while others prefer their belts to hang down to their feet. As that can come down to personal preference, let us then look at how you can get your belt just to the length that you want.

If you prefer it a little shorter, you can add 60-70cm to the result of your waist circumference times two. That should look something like this.

Or if you prefer it a little bit longer to really show the movement of your hips, you can add somewhere between 100 and 110 cm to your total and get a belt that hangs like this.

Of course, for some this is not enough. As they may need the entire name of their federation – along well as their mother’s middle name on the obi. (You know who you are.) For this you can add an extra 120-130cm to your obi to get some real hang.

Now that we have figured out how long your belt should be let`s look at how to wear It, there isn’t much fun in having a great belt if you don’t know how to wear it. Now again there are many different ways of wearing a belt and they are all totally fine, just make sure you check with your teacher before you come rolling into your Dojo with a triple over hand triple twist knot.

Let’s start by introducing the simplest – which is also the most widely used knot. This will keep your dogi closed tight and is also very easy to do. One thing to keep in mind about this knot is that it leaves the obi crossing over itself on your back, which means it can become uncomfortable if worn over a long period of time. Another small thing is that the knot is only held together by itself, which means that there is a tendency for it to untie itself after vigorous use. Please watch the video below for an easy to do way to tie your belt.

There is also another knot – which has been a preferred method of many individuals for a long time – as it does not cross over on the back and secures the loose ends of the belt under the belt, so it has very little chance of becoming loose and untying. It can be a little challenging if you have never tried this method before, but don’t give up easily, as it is a great knot.

Please also be aware that the knots can be combined in many different variations and there is a myriad of ways of getting to the end result, so please have fun discovering new and interesting ways of tying your obi. If you know any interesting ways to tie the belt that we missed, please let us know.