Putting on a gi is straightforward once you know the order: pants first, then the jacket with the left lapel crossing over the right, then the belt tied snugly at your waist. Getting these basics right matters more than you might think. The lapel direction has deep cultural roots, and a sloppy belt knot will come undone mid-training. Here’s how to do it properly from start to finish.
Start With the Pants
Step into the pants and pull the drawstring tight enough that they sit comfortably at your waist without sliding down. Most gi pants have a drawstring threaded through the waistband. Tie it in a simple bow or double knot at the front. Tuck the ends of the drawstring inside the waistband so they don’t dangle and get grabbed during training.
If your gi has a traditional wrap-style waist on the pants (common in some judo gis), fold the extra fabric flat against your hip before tying. The goal is a secure, flat waistband with no bunching.
Put On the Jacket: Left Over Right
Slide your arms through the sleeves and let the jacket hang open. Now close it by pulling your right lapel across your body first, laying it flat against your chest. Then fold the left lapel over the top of the right one. This left-over-right rule applies to every martial art that uses a gi: karate, judo, Brazilian jiu-jitsu, aikido, and others.
This tradition traces back to the Yōrō Clothing Code of 718, a Japanese decree that standardized clothing to be worn left side over right, following Chinese custom. One practical theory suggests wearing the left side on top kept the inside of the garment accessible to the right hand, useful for reaching concealed items or weapons. The convention stuck for over a thousand years and carries into modern martial arts.
Getting this wrong isn’t just a fashion mistake. In Japanese culture, right-over-left is reserved for dressing the deceased for burial. Wearing your gi the wrong way will draw immediate correction from any instructor who notices.
Tying the Belt: The Standard Knot
Fold your belt in half to find the center point. Place that center just below your belly button, pressing it flat against the front of the jacket. This keeps the jacket closed and the lapels in place.
Wrap both ends evenly around your waist, crossing them behind your back, and bring them back to the front. You should now have two tails of roughly equal length hanging in front of you. Cross the left end over the right. Take the end that’s now on top and tuck it underneath both layers of belt (the wrap around your waist and the piece you just crossed), pulling it through from bottom to top. Snug it down.
Now tie a square knot: cross the two ends again, right over left, then left over right. Pull both tails firmly away from your body to tighten. A proper square knot lies flat and horizontal. If your knot twists vertically or the tails point up and down instead of left and right, you’ve tied a granny knot. Untie it and try again. Practice this a few times at home and it becomes second nature.
The Super Lock Knot
If you train in Brazilian jiu-jitsu or another grappling art, you may find the standard knot comes undone constantly during rolling. The super lock knot (sometimes called the Hollywood knot) stays tied much more reliably. Start the same way: close your jacket left over right and place one end of the belt at your hip. Wrap the long tail around your waist and bring it back to the front. Instead of simply crossing and tying, loop one tail over the other end and then underneath the belt layers around your waist. Pull both ends away from your belly to tighten, then finish by crossing the higher tail over and under the lower one. The result is a knot that cinches down on itself and resists loosening even during intense grappling.
What to Wear Underneath
For casual training, most people wear a simple t-shirt or rash guard under the jacket and compression shorts or regular briefs underneath the pants. This keeps things comfortable and hygienic, especially since gi fabric can be rough against bare skin.
Competition rules are stricter. Under IBJJF (International Brazilian Jiu-Jitsu Federation) rules, men cannot wear a shirt under the gi top. Women are required to wear a fitted, stretchy shirt underneath, either short or long sleeved. Pants under the gi pants are prohibited for men. Women may wear elastic-fabric pants underneath as long as they’re shorter than the gi pants. Everyone must wear briefs-style undergarments; thong-type undergarments are not permitted.
How Different Gis Fit and Feel
Not all gis go on the same way in terms of how they’ll sit on your body, because the cut varies significantly by discipline.
- Karate gis are lightweight and stiff, almost like canvas. The sleeves and pant hems are wide, designed to snap audibly during strikes and hold their shape during stances. The jacket has a long skirt (called the cape) that tucks under the belt.
- Judo gis are thick and heavy, built to withstand constant grabbing and throwing. The sleeves are wide and long to give opponents grip room (this is by design, not a flaw). The pants, by contrast, are lightweight to help manage heat. The jacket’s skirt is cut short, so it tends to come untucked during sparring and needs to be tucked back in regularly.
- BJJ gis are slim-fitting compared to judo gis. The sleeves are long but tighter around the arms and wrists, reducing the fabric an opponent can grab. The pants are straight-legged and full length rather than the three-quarter length common in judo. The overall construction is lighter because BJJ relies more on ground grappling than throws.
When you put on your gi, the sleeves should reach your wrists (or slightly above for competition), and the pants should hit at or just above your ankle bones. If sleeves hang past your fingertips or pants pool around your feet, you need a smaller size.
Choosing the Right Size
Gi sizes use an alphanumeric system rather than small/medium/large. Adult sizes typically run from A0 to A5, with A0 being the smallest. Your height matters more than your weight for getting the right length. As a rough guide for men’s gis: if you’re between 5’1″ and 5’3″, an A0 covers most weight ranges. At 5’4″ to 5’6″ and around 155 to 200 pounds, you’ll likely fall into an A0 or A1 depending on your build. Kids’ gis use a separate scale (K0 through K3), with K0 fitting children around 3’1″ to 3’8″ and 30 to 45 pounds.
Keep in mind that gis shrink. A brand-new gi that feels slightly roomy will tighten up after a few washes, especially if you use warm water or a hot dryer. If you’re between sizes, many practitioners size up and then shrink the gi to fit rather than risk buying one that becomes too small.
Washing Without Ruining the Fit
Always wash your gi in cold water. Cold water cleans effectively while keeping shrinkage minimal and preserving the fabric’s strength. Hot water causes unnecessary shrinkage and accelerates wear on the fibers.
Air-dry your gi whenever possible. High-heat tumble drying weakens the fabric over time and can lead to tearing, especially along seams and in the collar. If you can’t wash your gi immediately after training, at least hang it open so air circulates through the fabric. A gi balled up in a gym bag for hours becomes a breeding ground for bacteria and odor that gets progressively harder to remove.
If your gi is slightly too large and you want to shrink it intentionally, run it through a warm or hot wash cycle, then tumble dry on high heat. Do this gradually, checking the fit after each cycle, because you can always shrink it more but you can’t stretch it back out.