Buying your first BJJ gi throws up a question that trips up almost every beginner: what on earth do A1, A2 and A3 mean? Gi sizing doesn’t follow normal clothing sizes, and getting it wrong means either swimming in fabric or failing a competition measurement check. This guide explains the A0–A6 system in plain English, shows you exactly how a gi should fit, and covers the things — shrinkage, cuts, brand variation — that the size chart alone won’t tell you.
How BJJ gi sizing works: the A-system
Brazilian Jiu-Jitsu gis use a universal sizing system that runs from A0 (smallest) up to A6 (largest). The “A” stands for adult, and the number is based on a combination of your height and weight — not your chest or waist measurement like a normal shirt.
The single most important thing to understand is this: height is the primary driver. Gi jackets and trousers are cut to a length, and you can’t easily fake length. If you’re caught between two sizes, your height usually decides it, then you adjust for build using the different “cuts” we’ll cover below.
BJJ gi size chart (A0–A6)
Use this as your starting point. It’s a general guide — always cross-check against the specific brand’s chart before you buy, for reasons we’ll explain in a moment.
| Size | Height | Weight |
|---|---|---|
| A0 | 5’2″–5’5″ (157–165 cm) | 55–64 kg |
| A1 | 5’5″–5’9″ (165–175 cm) | 64–75 kg |
| A2 | 5’9″–6’0″ (175–183 cm) | 75–84 kg |
| A3 | 5’11″–6’3″ (180–190 cm) | 84–100 kg |
| A4 | 6’2″–6’4″ (188–193 cm) | 95–110 kg |
| A5 | 6’3″–6’6″ (190–198 cm) | 105–125 kg |
| A6 | 6’5″+ (196 cm+) | 120 kg+ |
Notice how the ranges overlap. That’s deliberate — and it’s where most people get stuck. Read on.
How a BJJ gi should actually fit
Forget the chart for a second, because fit is something you can see and feel. A properly sized gi follows two simple rules, and these are the exact measurements an IBJJF referee checks at competition:
- Sleeves: the jacket sleeve should reach down to your wrist bone when your arm is held straight out, and no further than 5 cm up from it.
- Trousers: the trouser leg should reach down to your ankle bone, again within 5 cm.
If your sleeves are riding halfway up your forearm, the gi is too small. If your hands disappear, it’s too big. The body of the jacket should be snug but allow a full range of movement — you want to be able to throw your arms overhead and sit in guard without the collar choking you.
The thing the chart won’t tell you: shrinkage
Most BJJ gis are 100% cotton, and cotton shrinks. A brand-new gi often feels slightly long in the sleeves and trousers when it first arrives — and that’s usually intentional. After a few cold washes and air-dries, it settles into the perfect fit.
This catches beginners out constantly. They try on a fresh gi, decide it’s too big, and exchange it for a smaller size — then shrink that one into something they can’t get into. A few pointers:
- Many modern gis are sold pre-shrunk or “sanforised”, meaning shrinkage is minimal. Check the product description.
- If a gi is not pre-shrunk and you’re between sizes, sizing up and letting it shrink to fit is often the safer bet.
- Never tumble dry a gi to “shrink it to size” — heat is unpredictable and damages the fibres. Wash cold, hang dry. (We cover gi care properly in our guide on how to wash a BJJ gi.)
Different cuts: Long, Husky and Fitted
Because A-sizes are based on two measurements that don’t always move together, many brands offer cut variations so you can fine-tune the fit to your build:
- Standard (A1, A2…): the default cut, suits the height/weight ranges in the chart above.
- Long (A1L, A2L…): the body and weight range of the standard size, with the height of the next size up. Perfect if you’re tall and lean — say, 6’0″ but only 78 kg, where a standard A2 fits the body but the sleeves come up short.
- Husky / Heavy (A1H, A2H…): extra width through the torso, shoulders and thighs while keeping the standard height. Ideal for a broader, stockier build.
- Fitted (A1F, F1…): a tapered, slimmer cut — popular with smaller-framed and female grapplers.
Why an A2 isn’t always an A2: brand variation
Here’s the catch that surprises even experienced grapplers: an A2 from one brand will not fit the same as an A2 from another. The A-system is an industry convention, not a strict standard, so each manufacturer cuts to slightly different measurements. A Tatami A2 and a Venum A2 can feel noticeably different on the same person.
The takeaway is simple: treat the size label as a starting point, then check the specific brand’s size chart for the gi you actually want. Every gi on our site lists its own sizing — and if you’re ordering more than one brand, expect to land on different letters. You can browse the full BJJ gi range and compare charts side by side.
Caught between two sizes? Do this
If your height and weight point at two different sizes — which happens to loads of people — follow this order of priority:
- Prioritise the body fit. A gi that fits your torso but has slightly short sleeves is far more comfortable to roll in than one that fits your arms but billows everywhere.
- Factor in shrinkage. If the gi isn’t pre-shrunk and you’re on the borderline, lean toward the larger size.
- Match it to a cut. Tall and slim? Go Long. Broad and stocky? Go Husky.
Kids’ gi sizing is different
Children’s gis don’t use the A-system. They’re sized by a simple M (metres/measurement) system — M0, M1, M2 and so on — based purely on the child’s height. Because kids grow fast, it’s tempting to buy big and roll up the sleeves, but a gi that’s too long is a genuine trip hazard on the mat. Buy close to size and replace as they grow. See our kids’ BJJ gis for age and height guides.
Don’t forget the belt
Your first gi will usually include a white belt, so sizing that isn’t urgent — but belts have their own length sizing (typically A1–A4 matching your gi size, wrapping twice with enough left to tie). When you progress, our BJJ belts are all IBJJF-compliant and listed with length guides.
Get it right first time
To recap: gi sizing runs A0–A6 on height and weight, height leads, the sleeves hit the wrist and the trousers hit the ankle, cotton shrinks so account for it, and an A2 is never quite the same twice — so always check the brand’s own chart. Get those right and your first gi will fit like it was made for you.
Still deciding what else you need before your first class? Our beginner’s BJJ kit checklist covers the lot. Or browse the full BJJ collection — and if you’d rather be sized up in person, the team at our Aylesbury and Central London (Waterloo) stores will sort you out.