BJJ Gi Sizing Guide: Find Your Size with the Full Size Chart

A gi that fits well disappears during training. A gi that does not fit does the opposite: sleeves you push up before every grip, a jacket that strains across the chest, trousers that catch on your feet in guard. BJJ gis use a simple letter and number system, and once you understand it and compare your measurements with the chart below, you can order with confidence. This guide covers our custom gi sizes from kids M00 to adult A5, explains every column of the chart in plain words, and shows you how to measure yourself at home.

BJJ gi sizes explained (what A and M sizes mean)

Adult gis use A sizes, from A0 up to A5. A0 is the smallest adult size and each step up adds length to the jacket, width across the sleeves and length and room to the trousers. There is no direct conversion to small, medium and large, which is why two brands can size differently and why the chart, not the label, is what matters. Kids gis use M sizes, from M00, the smallest children's size, through M0, M1, M2 and M3. Our custom gis run in both systems: M00 to M3 for kids and A0 to A5 for adults, with some designs topping out at A4. Height and weight give a rough starting point, but build matters more: a tall, lean player and a shorter, broader player can weigh the same and need different sizes. That is why the chart below works in garment measurements, in inches.

The size chart

The chart uses four measurements, all in inches. A is the jacket length, measured from the collar down to the hem. C is the sleeve to sleeve span, measured across the back of the jacket from one cuff to the other. H is the pant length, from the waistband to the ankle. W is the pant waist measurement on our garment chart; measure a pair of gi pants that fits you, laid flat, and compare like for like.

Worked example: a jacket measuring about 32 inches in length and 67 inches cuff to cuff points to an A2. If your jacket and pant numbers suggest different sizes, prioritize the jacket: trousers have a rope drawstring and a rollable waistband, while a short or tight jacket cannot be adjusted.

How to measure yourself for a gi

The most reliable method uses a gi you already own. Lay the jacket flat, smooth it out, and measure the length from the top of the collar to the hem, then across from cuff to cuff with the arms stretched out to the sides. Lay the trousers flat and measure the waistband across, then the full length down to the ankle. Write the four numbers

down and match them to the chart. If you do not own a gi yet, use a tape measure on your body: your arm span, fingertip to fingertip, is a close guide to the C measurement, and your inside leg plus the rise of the trousers guides the H measurement. A training partner or a tailor can help you get clean numbers in a couple of minutes. Measure twice: one wrong number usually means one wrong size, and each of our gis is personalized, so the chart is worth the two minutes it takes.

Slim, regular and husky cuts (the S and H variants in the store chart)

Standard A sizes are the regular cut, but the store chart also carries two variants. The S variants, A0S, A1S, A2S and A3S, keep a similar body to the regular size and add length to the sleeves. They suit slimmer, longer armed builds: if regular sizes fit your chest but the cuffs land too far up your forearm, an S cut is your answer. The A2H is a husky cut, roomier through the body for broader builds that find the regular A2 tight across the chest, shoulders or waist. Choosing between them is simple: match your jacket length first, then pick the variant that matches your build. Long arms, choose S. Broad frame, choose H where it is listed. Everyone else stays with the regular cut.

Shrinkage: how much and how to prevent it

Cotton gis shrink about 3 to 5 percent if they are hot washed or tumble dried, and most of that shrinkage happens in the first few washes. Our gis are pre-shrunk, which means the fabric has already been treated to remove most of that movement before your gi is made. What remains is in your hands: wash cold and hang dry, and the size you ordered is the size you keep. Hot water and a hot dryer can still pull a pre-shrunk gi in, especially in the sleeves and jacket length. If you are between sizes and you know your gi will sometimes meet warm water, size up. If you always wash cold and hang dry, order your true chart size.

Kids and women's sizing

For kids, resist the urge to buy two sizes up for growing room. A little room is sensible, but an oversized gi means sleeves that cover the hands and trousers that bunch at the ankle, which makes training harder and less safe. One size of growing room is plenty, and the M sizes step up in small increments. For women, order from the same chart: the gis are unisex cuts, so compare your measurements rather than converting from dress sizes. The S variants help if you have long arms for your frame, the A2H adds room through the waist, and our women's collection page gathers the fit guidance in one place.

Frequently asked questions

How do I choose the right gi size if I am between sizes?

Compare your measurements with the chart and prioritize jacket length and sleeve span. If you fall between two sizes, pick the larger one if you are still growing, carry a broad build, or ever wash warm. Pick the smaller one if you wash cold, hang dry and prefer a close fit.

Will my BJJ gi shrink?

Our gis are pre-shrunk, but cotton can still shrink about 3 to 5 percent in hot water or a hot dryer. Wash cold and hang dry to keep the fit you ordered.

What size should I buy for my child?

Measure your child's current gi or use the M size rows of the chart, and allow no more than one size of growing room. Sleeves that cover the hands and trousers that drag make training harder.

What do the S and H sizes mean?

S sizes, like A1S, add sleeve length for slimmer, longer armed builds. The A2H is a husky cut with more room through the body. Regular A sizes suit everyone else.

Ready to order? Put your measurements to work in our custom BJJ gi collection, pick your size, GSM and colors, and add your name in embroidery: /collections/boxing-martial-arts