How to Choose a BJJ Gi: Sizing, Weave and Weight Explained

A gi that shrinks two inches in the first wash is not a defective gi. It is an untreated cotton gi behaving exactly as cotton does, bought by someone who was never told.

Choosing a BJJ gi involves three decisions that interact: the size letter, the weave, and the fabric weight. Get all three right and you have a uniform that fits after washing, survives years of training, and passes competition inspection without argument. Get any one wrong and you own an expensive bag of cotton that either swamps you or strangles you.

This guide covers how A0 to A6 sizing actually works, what the weave names mean in practice, how GSM translates to training experience, and the shrinkage question that catches nearly every beginner.

How BJJ Gi Sizing Actually Works

BJJ gis use a letter-and-number system, A0 through A6, where A stands for adult. Unlike apparel sizing, the letter maps primarily to height, with weight as a secondary check.

When your height and weight point at different sizes, follow the height. A gi that is too short in the sleeve fails inspection. A gi that is slightly loose in the body does not.

Some manufacturers add F sizes for women and H sizes for a huskier build, cut differently through the shoulders, hips and torso rather than simply scaled. If a standard cut has never sat right on you, those are worth trying before you conclude that gis do not fit you.

The measurements that decide inspection

Competition inspection is not about how the gi looks. Referees measure specific things, and the two that fail most often are sleeve and trouser length.

The jacket sleeve must reach close to the wrist when your arm is extended straight out, and the trouser must reach close to the ankle bone. There must also be enough space at the sleeve opening for a referee to slide a finger between the fabric and your forearm.

Measure to those points rather than trusting the size chart alone, because cut varies noticeably between brands even within the same letter.

Understanding Weave

Weave describes how the jacket fabric is constructed, and it determines durability, weight and how easy you are to grip.

Single weave is the lightest and least expensive. It breathes well, dries fast, and is easier for an opponent to grip. It also wears out fastest. A reasonable first gi and a good hot-weather option.

Double weave is dense, heavy and extremely durable, and much harder to grip. It is slow to dry and hot to train in, which is why it has fallen out of everyday use even though it lasts nearly forever.

Gold weave sits between the two. It aims for double-weave durability at closer to single-weave weight, and for years it was the default recommendation for a serious training gi.

Pearl weave has largely taken that position now. It is light, durable, dries reasonably quickly, and is what most competition gis are made from. If you want one gi that does everything acceptably, pearl weave is the safe answer.

Ripstop appears mostly in trousers and in travel gis. It is very light and resists tearing well, but it can feel slick and some competitions restrict it for jackets. Check before buying a full ripstop set for competition.

What GSM Actually Tells You

GSM means grams per square metre, and it measures fabric weight rather than quality. A higher number is not automatically better.

Light gis in the 350-450 GSM range are quick-drying, comfortable in heat, and easy to travel with. They also give your opponent less fabric to work with, which some players prefer. The trade-off is a shorter life under heavy training.

Mid-weight gis around 450-550 GSM are the everyday standard. This is where most pearl weave competition gis sit, and it is the range to buy if you are only buying one.

Heavy gis above 550 GSM last a long time and are harder to grip, but they are hot, slow to dry, and heavy to carry. If you train twice a day in a warm gym, you will resent one.

Trousers are usually quoted separately, and cotton drill or ripstop in the 8-12oz range covers most needs. Reinforcement matters more than raw weight here. Look for knee padding that extends well above and below the knee itself, because that is where trousers actually fail.

The Shrinkage Question

Most gi cotton shrinks, and how much depends on whether the fabric was pre-shrunk.

An unpre-shrunk cotton gi can lose one to two inches in sleeve and trouser length over the first few washes. A pre-shrunk gi will move very little. Manufacturers state which theirs is, and it is worth finding out before choosing your size rather than after.

If your gi is not pre-shrunk and you are between sizes, size up and let the first wash bring it in. If it is pre-shrunk, buy the size that fits now.

Washing so it stays the size you bought

• Wash cold, at 30C or below. Heat is what drives shrinkage
• Hang dry. A tumble dryer will shrink a gi faster than anything else you can do to it
• Wash after every single session, without exception
• Wash white gis separately, and wash coloured gis separately for the first few cycles because dye runs
• Skip fabric softener, which coats the fibres and reduces durability

Washing every session is not fussiness. Untreated gis grow bacteria quickly in a warm bag, and skin infections spread through grappling gyms faster than through almost any other sport.

Colour and Competition Rules

Most federations permit white, blue and black, and require a single solid colour throughout the gi. A white jacket with blue trousers will typically be refused.

Beyond colour, inspection commonly covers patch placement and material, collar thickness and width, overall fit at sleeve and trouser, and the condition of the fabric. Requirements differ between organisations and change between seasons, so read the current rulebook for the specific competition you are entering rather than relying on what was true last year.

For training, most gyms are relaxed about colour. Check whether yours has a rule before buying something unusual, because some academies require white for beginners.

Collar Construction and Grip Fighting

The collar is the part of a BJJ gi you will feel most during a roll, and it is the part beginners never think about when buying.

Collars are filled with either cotton or rubber. Cotton is softer, more comfortable, and absorbs sweat, which means it gets heavier and slower to dry through a session. Rubber-filled collars stay firmer, dry faster, and are considerably harder for an opponent to grip and hold.

Thickness matters for the same reason. A thick, stiff collar is harder to close a hand around, which is a real defensive advantage in grip fighting. It is also less comfortable and takes longer to break in.

Federations set limits on collar thickness and width, and this is one of the specific things measured at inspection. A collar built for maximum grip resistance can be refused, so check the current limits if you are buying specifically for competition.

Skirt, vents and stitching

The jacket skirt takes a lot of stress from being gripped and pulled. Look for reinforcement stitching along the side vents and around the bottom hem, because that is where jackets split first.

Shoulder and armpit seams are the other failure point. Multiple rows of stitching there is a better indicator of a gi's lifespan than the price tag or the weave name.

When to Replace a Gi

A gi does not fail suddenly. It degrades in ways that are easy to ignore until a training partner points them out.

Signs it is finished:

• Splits at the side vents or under the arms, which spread quickly once started
• A collar that has gone soft and folds flat, offering no grip resistance
• Trousers worn thin at the knee, which is a tear waiting for a hard scramble
• Fabric that stays smelling stale after a proper wash, meaning bacteria has embedded in the fibres
• Sleeves or trousers that have shrunk past the inspection line

That last one catches people mid-competition season. Measure your gi against the sleeve and ankle requirements once a year rather than discovering the problem at weigh-in.

A well-chosen mid-weight pearl weave washed cold and hung dry should give you two to four years of regular training. A cheap single weave washed hot might give you eight months.

Questions We Get Asked Most

Should I size up for shrinkage?

Only if the gi is not pre-shrunk. Manufacturers state this, and it is worth checking before ordering. A pre-shrunk gi should be bought in the size that fits now, because it will barely move.

How many gis do I need?

Two, before you buy one expensive one. Gis take a full day to dry properly when hung, and training in a damp gi is both unpleasant and a skin-infection risk. Two mid-range gis beat one premium one for anyone training more than twice a week.

Why did my white gi turn grey?

Almost always washing it with coloured gis, or with anything else at all. Wash white separately, and wash new coloured gis separately for the first several cycles because the dye runs heavily at first.

Can I use a judo gi for BJJ?

You can train in one, and plenty of people do. Judo gis are cut looser through the body and sleeve, which gives your opponent more fabric to grip, and the looser sleeve may fail BJJ inspection. For competition, buy a BJJ-specific gi.

What is the difference between A2 and A2L?

L means long. Some manufacturers offer long variants at the same nominal size for players who are tall for their weight, with extra sleeve and trouser length but the same body width. If you are consistently failing the sleeve measurement despite the right weight, that is what you want.

Do I need to buy a belt separately?

Almost always yes. Very few gis include one, and your belt rank is yours regardless of which gi you are wearing. Buy a belt in the correct length for your waist rather than the one that matches the gi.

Is a heavier gi better?

No, just different. Heavier fabric lasts longer and is harder to grip, but it is hot, slow to dry and heavy to carry. Mid-weight pearl weave around 450-550 GSM is where most people land for good reason.

Choosing Your First Gi

If you are buying your first gi and want a single recommendation: a pre-shrunk pearl weave in the 450-550 GSM range, sized by height, in white or blue.

That combination fits after washing, survives regular training, passes inspection nearly everywhere, and does not cook you in a warm room. Once you have trained in it for six months you will know whether you want something lighter for summer or heavier for durability, and you will be making that second decision with actual information rather than guesswork.

Buy two before you buy one expensive one. Training in a damp gi because your only one has not dried is worse than owning two cheaper ones.

Our martial arts uniforms range covers BJJ gis alongside judo gi, karate gi and taekwondo dobok, with weave and GSM listed on every product. If you are between two sizes or unsure whether a gi is pre-shrunk, contact us with your height and weight and we will confirm before you order.