The gi is the most important piece of kit you’ll own as a grappler — and the one most often bought wrong. Get the size wrong and it either swims on you or fails the measurement at registration. Get the weave wrong and you’re either cooking through summer rounds or replacing it inside six months. After more than fifteen years on the mats and designing gis worn by the members of our own Melbourne gym, we’ve seen every sizing mistake there is. This guide covers everything that actually matters — size, weave, weight, pants, competition rules and care — so you buy once and buy right.
Start with size: the A-system explained
BJJ gis use the “A” sizing system — A for adulto. Adult sizes run from A00 (smallest) through A5 (largest), with A1, A2 and A3 covering most adults. Some brands add “L” variants — A1L, A2L — for taller, leaner builds: extra length in the sleeves and pants without extra width.
Unlike a t-shirt, gi sizing is driven by height first, then weight. A size chart gives you a height range and a weight range for each size. If you fall between two sizes, prioritise height (so your sleeves and pant cuffs pass the check at competition) and use weight to fine-tune the fit. Every BUDO gi has its own chart on the product page — always check it, because sizing varies between brands and even between models.
The detail that catches people out: shrinkage
Cotton shrinks. A gi that isn’t pre-shrunk can lose close to a full size in its first few hot washes, which is why some brands tell you to “size up” and hope. We pre-shrink all our fabric before it’s cut, so what you order is what you keep — order true to the size chart, no guesswork. If you’re buying a gi that isn’t pre-shrunk, factor the shrinkage in and wash it cold from day one.
Weave and weight (GSM): what the numbers mean
The “weave” is how the jacket fabric is knitted, and it’s where most of a gi’s character comes from. You’ll see a few terms:
• Single weave: light and cheap, but wears out faster.
• Double weave: very heavy and durable, but hot — rare these days outside judo.
• Pearl weave: the modern standard, and what we use. It hits the sweet spot — light enough to move and breathe, tough enough to take years of grips.
Pearl weave is measured in GSM (grams per square metre) — essentially how dense and heavy the fabric is. As a rule of thumb, lighter (around 350–400gsm) means a faster-drying gi favoured for competition; heavier (450gsm and up) means a more substantial gi built for daily training. Our standard gis are a 450gsm pearl weave, built to survive relentless training. Our competition edition drops to 380gsm, shaving weight for the scales and for speed on the mat.
Training gi or competition gi?
If you train several times a week and want one gi that lasts, go heavier — our 450gsm workhorse. If you compete and want to make weight more easily and move light, a 380gsm competition gi earns its place in the bag. Plenty of serious grapplers end up with both: a durable gi for the training week and a lighter one for comp day.
Don’t overlook the pants — or the collar
Older gis used heavy cotton drill: durable, but heavy and slow to dry. Most modern gis, ours included, use ripstop — a lightweight woven fabric with a grid pattern that resists tearing. Our pants are a ripstop poly-cotton blend: light, fast-drying and hard to rip, with reinforcement where you need it and a solid drawcord. Look for belt loops that won’t tear out under a hard grip.
One more thing people miss: the collar. A good gi has a firm-but-flexible collar that’s harder for your opponent to grip and choke with. We use an EVA foam collar wrapped in fabric that matches the pants — it resists soaking up sweat (and the smell that comes with it) and dries fast.
Competing? The IBJJF rules that decide if your gi passes
If you’re going to compete — especially under IBJJF rules, which most Australian competitions follow — a few requirements decide whether your gi clears the check at registration:
• Colour: only solid white, royal blue or black are allowed, and the jacket and pants must be the same colour.
• Fabric: a cotton or cotton-like weave, not so thick or rigid that it stops your opponent gripping.
• Fit: when you raise your arm, your sleeve and pant cuffs can’t sit too far up the limb — referees measure this at check-in, which is exactly why height-based sizing matters.
Rules do change, so always confirm the current IBJJF requirements for your division before you buy. To make it easier, our IBJJF-friendly cuts are grouped together so you don’t have to guess.
Make it last: caring for your gi
A premium gi will outlast a cheap one many times over — if you look after it. A few habits make all the difference:
• Wash cold (30°C or less) and inside out. Hot water is what shrinks and fades.
• Hang dry, never tumble dry. The dryer is the single fastest way to shrink and wear out a gi.
• Wash after every session. Bacteria — and the dreaded mat funk — build up fast.
• Skip the bleach on colours; for whites, use a gentle oxygen-based whitener rather than chlorine bleach.
Do this and a 450gsm pearl weave will give you years of hard training.
A note on women’s and kids’ gis
Women’s gis (often using “F” sizing) are cut for a different frame — buying a small men’s gi usually means a poor fit, so look for a proper women’s cut. For kids, prioritise a gi tough enough for constant washing with a little growing room without drowning them. Our kids’ range is built and sized for exactly that.
Quick checklist before you buy
• Checked the size chart for this specific gi (height first, then weight)?
• Is it pre-shrunk — or do you need to size up?
• Right weight for the job: 450gsm for training, lighter for competition?
• Competing? Colour and fit IBJJF-legal?
• Happy to wash cold and hang dry to make it last?
Tick those five and you’ll buy once and buy right.
Find your fit
Every BUDO gi is designed in Melbourne — the home of Australian jiu-jitsu — pre-shrunk, reinforced and triple-stitched, and tested on the mats of our own gym before it ever reaches you. Browse the full BJJ gi range and check the size chart on any model to find your fit.