IBJJF Gi Rules: What's Legal at a Jiu-Jitsu Tournament

Every IBJJF tournament has a quiet checkpoint that eliminates people before they ever touch the mat: the uniform inspection. A sleeve that is a little too short, a collar that is too thick, a patch in the wrong place or a rash guard under a man's gi can stop you at the table after months of preparation. This guide walks through the IBJJF gi rules as written in the federation's current Rule Book (the June 2024 edition), what the inspector actually measures, and how our competitors in Gallatin, TN get their gear ready so the only thing they have to think about on the day is the match.

Everything below comes from Article 8 of the IBJJF Rule Book, which covers obligations, bans and demands for athletes. Smaller local events often borrow these rules too, so it is worth knowing them even if your first tournament is not an IBJJF event. Always read the specific event page before you register, because organizers can add their own requirements.

IBJJF Gi Rules at a Glance

If you only remember one section, make it this one. To pass inspection, your gi has to be:

• The right color. Completely white, royal blue or black. The jacket, pants and collar all have to be the same color.
• The right fabric. Cotton or a cotton-like fabric that is not so thick or hard that an opponent cannot grip it. For juvenile, adult and master divisions, a woven (pearl weave) gi is mandatory.
• The right fit. Sleeves within 2 cm of your wrist with your arm extended, pants within 2 cm of your ankle bone, and a jacket that reaches your thigh.
• The right collar. No thicker than 1.3 cm and no wider than 5 cm.
• In good condition. No tears, no mending, not wet, not dirty and not smelling bad.
• Patched correctly. Patches only in the authorized regions, made of cotton and properly sewn on.

Add a belt that meets the rules, the right undergarments and short nails, and you are most of the way there. The rest of this post explains each of those in detail.

Gi Color, Fabric and Condition

The color rule is simple and strict. A white jacket with blue pants is not allowed, and neither is a white gi with a black collar. Painted gis are also forbidden, with one exception: paint in the shape of an academy or sponsor logo is allowed, but only in the regions where patches are permitted, and you will be made to change if the paint marks your opponent's gi.

In adult black belt divisions, organizers can require athletes to bring two gis, one royal blue and one white, so the referee can tell the two competitors apart. Below black belt this is not a rule, but bringing a second legal gi is good practice anyway (more on that below).

Fabric matters more than most people expect. The rule says the material must not be so thick or stiff that it keeps an opponent from gripping it, and juvenile, adult and master athletes must wear a woven pearl weave gi. Foam (EVA) or similar material inside the collar is allowed, as long as the collar still meets the size and rigidity limits.

Condition is the easiest rule to follow and one of the most common reasons people get turned away. A gi with a torn sleeve, a visible repair, or one that is still damp from last night's wash will not pass. Pack it clean, dry and in one piece.

Measurements the Inspector Checks

Before you weigh in, a uniform inspector checks your gi against the regulations, usually with a measuring tool built to the IBJJF specs. These are the numbers in the Rule Book:

The sleeve and pants rules are the ones that catch people. Gis shrink, especially in a hot dryer, and a gi that fit perfectly when it was new can be several centimeters short a year later. Check your competition gi at home with your arms straight out in front of you. If the sleeve ends well above your wrist, it is time for a new one or a larger size.

The sleeve width rule exists for grip fairness. Tight, fitted sleeves are harder to grab, so the inspector checks that there is enough room inside the sleeve along its full length. You get three inspection attempts, and the inspector also looks at the general condition of your belt.

Belts, Patches and What You Wear Underneath

Your belt

Your belt has to be durable, 4 to 5 cm wide and the color of your rank, with a black tip (black belts use a white or red tip). It goes on over the jacket, wraps around the waist twice, and is tied with a double knot tight enough to hold the jacket closed, with each end hanging 20 to 30 cm.

Patches

Patches and embroidery are only allowed in authorized regions of the gi, which the Rule Book shows in a set of illustrations. They must be cotton and properly sewn. If a patch is loose or sits in an unauthorized spot, the inspectors will remove it. A thin fabric brand tag (at most 36 square cm) is allowed on the front lower part of the pants. Patches or text with political, offensive or violent messages, or that promote drugs, alcohol or tobacco, are banned.

Most store-bought gis come with patches in legal places. The risk is the custom patch you sewed on yourself. If you are not sure, compare it against the illustration in the official Rule Book before the event.

Under the gi

• Men: no shirt or rash guard under the jacket, and no pants of any kind under the gi pants.
• Women: a stretchy, close-fitting shirt under the jacket is mandatory. It can be short or long sleeved and any color. A one-piece swimsuit or gymnastics top is also allowed, and women may wear elastic pants under the gi pants as long as they are shorter than the gi pants.
• Everyone: brief-style undergarments are mandatory at every IBJJF event, gi or no-gi. Not wearing them is treated as a severe foul under the Rule Book.

Plenty of people wear a rash guard under the gi in regular class, and that is fine for training. Just do not show up to an IBJJF men's division with one on.

Hygiene and Equipment Rules

The inspection is not only about fabric. The IBJJF also requires:

• Fingernails and toenails trimmed short.
• Long hair tied up so it does not bother your opponent. Hair pins and jewelry are not allowed.
• No hair dye or makeup that stains your opponent's gi, which is grounds for disqualification.
• No creams, oils or slippery substances on your body or gi.
• No hard protective gear that could hurt either athlete, and no joint braces bulky enough to make the gi harder to grip.

After weigh-in, the gi inspector also checks for skin conditions. An athlete with a skin lesion is sent to the event's medical area, and the tournament doctor has the final say on whether they compete. If you have anything on your skin you are unsure about, see your own doctor before the event, not the morning of.

Competition Day: Weigh-In and Changing Gis

At IBJJF events you are weighed right before your first match, and you step on the scale in your gi (no shoes, nothing extra). That is one reason the gi you bring matters: a heavy gi counts against your weight. Our upcoming guide to IBJJF weight classes will cover how to pick a division.

The rule that surprises first-time competitors: once you weigh in, you cannot change your gi before your first match. Doing so means disqualification. After that first match you can ask the Ring Coordinator for permission to change, and the new gi has to pass its own inspection before you fight in it.

A simple checklist our competitors use the night before:

1. Pack two legal gis, clean and fully dry, with patches checked.
2. Measure the sleeves and pants one more time.
3. Pack your belt and the right undergarments.
4. Trim fingernails and toenails, and pack a hair tie if you need one.
5. Read the event page for anything specific to that tournament.

Preparing for these details is part of what our BJJ Fight Team in Gallatin covers alongside match strategy and hard rounds. If you have general questions about gear, classes or getting started, our jiu-jitsu FAQ answers the most common ones.

IBJJF Gi Rules for Kids and Teens

Young competitors follow the same color, fit, belt, patch and hygiene rules as adults. The pearl weave requirement is written for the juvenile (16 and 17), adult and master divisions, but buying a standard pearl weave kids gi from a reputable brand is the simplest way to stay legal. Kids also outgrow gis fast, so measure your child's sleeves and pants a week before every event, not the night before.

Kids divisions have their own limits on which techniques are allowed, which we cover in our guide to the types of chokes in BJJ. If you are still deciding whether jiu-jitsu is right for your child at all, start with what parents ask most about jiu jitsu for kids.

A Note on No-Gi

IBJJF no-gi events have their own dress code: a skin-tight shirt covering the torso to the waistband, in black, white or black and white with at least 10% of your belt color (or fully in your belt color), plus shorts with no pockets, buttons, zippers or metal that reach at least halfway down the thigh but not past the knee. We will cover no-gi in more depth in a future post.

Competing is never required at GMA, and most of our students never enter a tournament. For the ones who do, getting the uniform right is the easiest win of the day. Take care of it at home and you walk up to the inspection table with nothing to worry about.

Frequently Asked Questions

Filed under: IBJJF, gi rules, competition, uniform check, Gallatin