When you buy a judo gi, three things matter: the weave weight (how heavy and thick the fabric is), the cut, and the size, often given in centimeters based on your height. Beginners do best with a light or mid-weight gi. Competitors move to a double weave that meets the rules for their level, and to an IJF-approved model for international events.
A quick word on names. The official term is judogi, often shortened to judo gi or just gi. Many people call it a "judo kimono", which is a common misnomer: a kimono is a Japanese robe, not a training uniform. All these words point to the same thing in a shop.
Judo gi weave and fabric weight
Fabric weight is usually given in grams per square meter. The higher it is, the thicker, heavier and harder to grip the fabric. Every maker has its own figures, but gis fall into three families.
| Type | How it feels | Who it suits |
|---|---|---|
| Light (thin single weave) | soft, dries fast, tears more easily | kids, toddler classes, light fitness judo |
| Mid-weight | good balance of comfort and durability | beginners and regular club players |
| Heavy (double weave) | thick, stiff at first, hard to grip | competitors, judoka who train a lot |
A double weave is not a luxury only for champions. Its stiffness makes it harder for opponents to grip, and it stands up better to constant pulling. On the other hand, it is heavy, hot and slow to dry. For a six-year-old, it is the wrong choice.
Our view: an adult who trains twice a week and does not compete does not need a double weave. A good mid-weight gi will last for years.
The cut: what to look for
A judo jacket should be long enough to cover the hips and loose enough to leave space between your arm and the sleeve. Sleeves should reach the wrist. The collar (eri) is thick and stiff on competition models and softer on training gis.
The pants reach the ankle and tie with a drawstring. Watch out for pants that end up too short after washing. They are often the first part to shrink.
Cuts vary between makers. Some run loose, others slim. If you have an unusual build, very tall and thin or short and stocky, try a gi on before buying whenever you can.
Picking a size from your height
Many brands label judo gis in centimeters: 150, 160, 170, 180 and so on. The number roughly matches the wearer's height, so an adult who is 175 cm tall looks at sizes 170 and 180. Other brands use a numbered scale (0, 1, 2 and up), which is common in North America. In that case, read the brand's own chart.
A few rules of thumb:
- between two sizes, go up if the gi is not preshrunk;
- with a heavy build, go up one size for room in the jacket;
- for a growing child, one size up is enough, not two, or they will trip over the pants.
You will find edge cases and a full reference table in our judo gi size chart.
Shrinkage, the nasty surprise
A cotton gi can lose several centimeters in its first wash, mostly in sleeve and pant length. Some makers sell preshrunk models that have already been treated. The label or product page usually says so.
To limit the damage, wash at a low temperature, skip the dryer, and hang the gi or lay it flat. Our guide on how to wash a judo gi covers the details. A gi bought at your exact size and washed hot can be too short within a few weeks.
IJF rules for competition
At competitions, your judogi gets checked. International Judo Federation (IJF) rules require sleeves that reach the wrist, enough overlap of the jacket at belt level, and precise collar dimensions. Officials use a measuring tool called a sokuteiki. Women wear a white T-shirt under the jacket, as explained in our article on women's judo.
For official international events, the gi must carry an IJF approval label. For regional and national events, requirements vary by level and by federation. Check with your club or your federation's rulebook before you spend money. Color rules are covered in our article on blue and white judogi rules.
A gi that is too tight or too short can get you asked to change, or even penalized. One more reason to get the size right. The general principles are in our overview of judo rules.
Judo gi vs BJJ gi
They are different uniforms. A Brazilian jiu-jitsu gi is shorter, more fitted and reinforced at the knees for ground work. It comes in several approved colors. A judo jacket is longer and roomier, because gripping the fabric is at the heart of stand-up judo.
If you train both, two separate gis remain the best answer. Our BJJ gi buying guide covers the Brazilian side.
What to buy for your profile
A child starting out: a light gi, one size up, nothing more. They will stain it, wear it out and outgrow it in two seasons.
An adult beginner: a mid-weight, preshrunk if possible. A regional competitor: a double weave suited to the rules at their level, plus a second gi to rotate while the first one dries. An international competitor has no choice to make: an IJF-approved model.
One last tip for everyone. Before you cut off the tag or wash a new gi, put the whole thing on and stretch your arms out in front of you. If the sleeves already ride above your wrists, exchange it right away. After the first wash, it will be too late.