How to Choose Your BJJ Gi Size: Step-by-Step Guide
A practical, step-by-step method for picking a BJJ gi that fits correctly, fights legally, and lasts through years of training.
In this guide
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A gi that fits wrong is more than uncomfortable. Sleeves that are too long give opponents extra fabric to grip and control. A jacket that’s too short can get you disqualified in competition for not covering your gi pants properly. And a gi that’s too tight restricts the exact movements you need for guard passing, escapes, and takedowns.
Getting sizing right the first time saves you money too. Gis aren’t cheap, and buying the wrong size means either living with a bad fit or eating the cost of a second purchase. This guide walks through the exact process coaches and experienced grapplers use to nail their size on the first try.
Step-by-step
Measure your height without shoes
Stand against a wall with your heels touching the baseboard and have someone mark the top of your head. Most BJJ size charts are built around height in centimeters or inches as the primary sizing variable, so this number matters more than almost anything else. Round to the nearest half inch and write it down before you do anything else.
Weigh yourself accurately
Step on a scale first thing in the morning, ideally without heavy food or water in your system, since that’s how most brands calibrate their charts. Weight matters because two people of the same height can have very different builds, and brands use weight as a secondary check to catch outliers. If your weight sits between two size brackets, lean toward the size that matches your height first.
Measure your wingspan for sleeve length
Stand with your arms stretched out to the sides like a T and have someone measure from fingertip to fingertip. This tells you whether you have long arms relative to your height, which matters a lot for sleeve fit. Grapplers with long arms often need to size up even if their height and weight point to a smaller gi, otherwise the sleeves will end above the wrist.
Check the brand's specific size chart, not a generic one
Every gi brand sizes differently. A size A2 from one company can fit completely differently than an A2 from another, even though the label looks the same. Pull up the exact chart for the specific gi model you’re considering and match your height and weight to their numbers rather than assuming your usual size will carry over.
Factor in shrinkage before you buy
Cotton and cotton-blend gis shrink, sometimes significantly, especially in the first two or three washes. If a gi is 100% cotton and not pre-shrunk, size up slightly or plan to wash it in cold water and air dry to control shrinkage. Ripstop and gold-weave blends shrink less, so you can generally trust the size chart more closely with those.
Check pant length and waist drawstring range
Gi pants use a drawstring rather than a fixed waistband, so the waist range is usually forgiving. Length is the bigger concern: pants that are too long bunch up around the ankles and get stepped on during drilling, while pants that are too short ride up and can expose skin, which is a problem in competitions with strict rules on gi coverage.
Try on the jacket and check the skirt closure
The jacket’s “skirt,” the bottom hem where the two sides overlap when tied with your belt, should close with at least a few inches of overlap. If you can barely close the skirt or it gapes open, the jacket is too small or too large respectively. This test is one of the most reliable ways to confirm fit once you actually have the gi in hand.
Test sleeve and pant length with arms raised and knees bent
A gi that fits standing still can ride up completely during a scramble. Raise your arms overhead and check that sleeves don’t pull up past your forearm, then squat down and check pant legs don’t rise above your shin. Movement testing catches fit problems a static mirror check will miss.
Compare against a gi you already own
If you have a gi that fits well, lay a new one flat next to it and compare jacket length, sleeve length, and pant inseam directly. This side-by-side comparison is often more reliable than trusting numbers on a size chart alone, especially if you’re switching brands.
Roll or drill in it before removing tags if allowed
If the seller’s return policy permits, do a light training session in the gi with tags still attached before committing. Fit issues that aren’t obvious standing still, like a collar that’s too stiff or sleeves that ride up during a triangle attempt, show up fast once you’re actually moving and gripping.
Common mistakes to avoid
Don’t size based on the shirt or pants size you wear in regular clothing. Gi sizing systems are built around competition standards and grip-fighting mechanics, not everyday fashion fit, so an A2 or size 3 gi has nothing to do with a medium t-shirt.
Don’t ignore the fabric weight when thinking about shrinkage. A lightweight 350gsm ripstop gi behaves very differently in the wash than a heavyweight 550gsm single-weave, and treating them the same way is a common reason people end up with a gi that no longer fits after a month of training.
Don’t buy a gi two sizes too big thinking you’ll “grow into it.” Loose gis are actually easier for opponents to grip and control, which works against you, not for you. If you’re between sizes and worried about shrinkage, buy one size up at most, and only if the fabric is untreated cotton.
Don’t forget that competition rules on gi fit are stricter than casual training standards. If you plan to compete, check the current IBJJF rules on jacket and pant length before your event, since a gi that’s fine for class can still get you flagged at weigh-ins.
Tips from the gym
Ask your coach or training partners what brand and size they wear if they have a similar build to you. Word-of-mouth sizing advice from people who train at your gym is often more useful than any online chart, because they can tell you how a specific gi actually behaves after real wear and washing.
If you’re buying your first gi, go with a mid-weight pearl weave or gold weave rather than the heaviest single-weave option. Mid-weight gis are lighter to train in, dry faster, and are generally more forgiving with sizing since they shrink less aggressively than heavier cotton weaves.
Kids’ gis run through sizes fast, so expect to size up more frequently for young grapplers than for adults. Buying slightly ahead of current measurements makes more sense for a growing kid than it does for an adult whose measurements are stable.
Once you’ve settled on a size that fits, always wash your gi in cold water and hang dry it to keep that fit consistent over time. Our guide on how to wash a BJJ gi without shrinking it covers the exact process to keep your sizing stable wash after wash.
Recommended gear
These are solid starting points for anyone sizing up a first or replacement gi. Always cross-check your measurements against the specific listing’s size chart before ordering.
- Fuji BJJ Gi – a reliable mid-weight option with a well-documented size chart that’s popular for beginners.
- Hayabusa BJJ Gi – a pre-shrunk, lightweight pearl weave that holds sizing well across repeated washes.
- Sanabul Essentials BJJ Gi – a budget-friendly option with a wide range of sizes, good for trying out fit before investing in a premium gi.
- Gameness Pearl Gi – a competition-legal choice with consistent sizing that’s well known in the IBJJF competition scene.
If you’re still deciding whether gi or no-gi training is the right fit for you, our guide on gi vs no-gi BJJ breaks down the gear and cost differences. And once you’ve got your gi sorted, browse the rest of the BJJ & Grappling hub for mats, belts, and other essentials.
Frequently asked questions
What size BJJ gi should I buy if I'm between two sizes?
Size down for a 100% cotton gi that hasn’t been pre-shrunk, since it will shrink further with washing. Size up if the gi is ripstop, gold weave, or already pre-shrunk, since those fabrics shrink very little and a too-small gi won’t loosen up over time.
How much do BJJ gis shrink after washing?
Untreated cotton gis can shrink noticeably, sometimes an inch or more in length and sleeve size, mostly in the first two or three washes. Pre-shrunk cotton and ripstop blends shrink much less, often less than half an inch, if washed in cold water and air dried.
Do kids need a different sizing approach than adults?
Yes, kids’ gis are sized on their own charts based on height and weight, and children tend to outgrow gis faster than adults, so it’s common to size slightly ahead of current measurements. Check the specific brand’s kids chart rather than guessing based on age alone.
How should gi sleeves fit for competition?
Most competition rulesets, including IBJJF, require sleeves to reach no further than the wrist bone when your arm is extended, with limited room past that. Sleeves that are too long or too baggy can result in a fit check failure at weigh-ins, so check the official rulebook if you plan to compete.
Can I return a gi if it doesn't fit?
Check the seller’s return policy before buying, since many allow returns if tags are still attached and the gi hasn’t been washed. Trying it on and doing light movement testing without full training first is a good way to confirm fit before removing tags.
Is gi sizing the same across all brands?
No, sizing varies significantly between brands even when using the same size labels like A2 or size 3. Always check the specific chart for the exact gi model you’re buying rather than assuming your size from one brand carries over to another.
