BJJ gi sizing is the detail that decides whether a customer keeps your gi or returns it. The A-size system confuses first-time buyers, shrinkage confuses everyone, and grading differences mean a size that fits from one label is wrong from another. This guide explains how gi sizing works and how to build a chart your customers can trust.
How the A-Size System Works
Adult BJJ gis are sized with an A followed by a number, from A0 up to A5 or A6. The number rises with height and build, and each step up lengthens the jacket and trousers while adding room through the chest, shoulders and waist.
Because there is no enforced industry standard, an A2 from one brand may not match an A2 from another, which is why your own measured size chart matters more than the label.
Adult Size Chart Basics
Most charts pair each size with a height and weight range, which together predict fit better than either alone: athletes of the same weight can need different sizes.
Typical adult ranges look broadly like this, though every brand should publish its own measured version:
- A0: roughly 150–160 cm and 45–55 kg
- A1: roughly 160–170 cm and 55–70 kg
- A2: roughly 170–180 cm and 70–85 kg
- A3: roughly 180–190 cm and 85–100 kg
- A4: roughly 190–200 cm and 100–115 kg
- A5 and above: for athletes above those ranges, with extra length and width
Kids’ and Women’s Sizes
Children’s gis use their own scales, often labelled M in Brazilian tradition or simply by height in centimetres. Kids grow fast, so parents typically size up, and your chart should say so honestly.
Women’s gis, usually labelled F or W, are cut narrower through the shoulders and hips with shorter sleeves. A genuine women’s pattern, rather than small men’s sizes, is a clear quality signal.
Measuring a Gi You Already Own
The most reliable sizing method is comparison. Ask customers to lay a gi that fits them flat and measure the jacket across the chest, the sleeve from centre back to cuff, and the trouser outseam, then compare those numbers with your chart.
Publish those garment measurements for every size you sell; brands that list real centimetre measurements see fewer size exchanges.
Sleeve and Trouser Length
Fit problems concentrate at the extremities. Sleeves should end near the wrist bone with arms extended forward, and trousers should finish above the ankle without pooling on the foot. A jacket that fits the chest but drowns the arms usually means the athlete sits between sizes.
Some brands offer in-between cuts, such as long (L) or husky (H) variants. These add pattern work but solve the most common complaint in gi sizing: the tall, lean fighter standard grading fails.
Training Fit vs Competition Fit
Everyday training gis are often cut slightly relaxed for comfort and layering over a rash guard. Competition cuts run closer to the body, with less loose fabric for opponents to grip and measurements that sit closer to the minimums officials allow.
Federations publish their own gi measurement rules, which change over time. If your customers compete, advise them to check their federation’s current rulebook before choosing a size.
Shrinkage: How Much to Expect
Cotton shrinks, and a new gi can come up noticeably shorter after its first hot washes. Untreated fabrics move most, and the jacket tends to shrink in length more than width.
Smart buyers wash cold and air dry to limit the change. Smart brands design for it, pre-shrinking the fabric or cutting with a shrinkage allowance, and say which they used.
Pre-Shrunk vs Untreated Fabric
Pre-shrunk gis use fabric washed or treated before cutting, so most shrinkage happens in advance and the size on the label stays close to the size after washing.
Untreated gis cost less to produce but demand honest guidance. At FORM FIGHT, sample gis made in Sialkot are measured before and after repeated washing, so a brand’s chart can show the post-wash fit that customers will actually experience.
Between Sizes: What to Advise Customers
Every range has borderline customers. If an athlete falls between sizes, the deciding factors are shrinkage and intended use. For an untreated gi they will wash warm, the larger size is usually safer; for a pre-shrunk competition gi, the closer fit may be the right call.
Put that advice on your product page in plain language; an honest sizing note prevents more returns than any table and builds trust with academies.
Sampling Before a Bulk Order
Never grade a full run from one sample. Fit the smallest, middle and largest sizes on real athletes, roll in them, wash them as a customer would and measure again.
FORM FIGHT supports this process with graded samples across your chosen range, so corrections to sleeve length or trouser rise can be made once, on the pattern, instead of across a finished production run.
Building a Size Chart for Your Brand
A trustworthy chart has four elements: height and weight ranges, actual garment measurements, a note on shrinkage, and guidance for between-size buyers. Add a diagram showing where each measurement is taken.
Our martial arts uniforms team can help you structure patterns and grading for a new gi range, and our capabilities page explains how sampling and pattern development work in practice.
Conclusion
BJJ gi sizing stops being mysterious once you treat it as three jobs: grade the pattern honestly, publish real garment dimensions, and design for the shrinkage cotton always produces.
If you are developing a gi range and want sizing you can publish with confidence, contact FORM FIGHT through our request a quote page and we will help you build the chart from measured samples.
FAQs
What BJJ gi size am I if I am 178 cm and 82 kg?
On most charts that falls squarely in A2, but always compare the brand’s garment measurements because grading differs between labels.
How much does a BJJ gi shrink?
It varies with fabric and washing, but untreated cotton can lose several centimetres in length over the first washes, while pre-shrunk gis change very little.
Should I size up for a growing teenager?
Yes, most parents size up one step for juniors, provided the sleeves are not so long that they become a safety or gripping problem in training.
Why does my A2 fit differently from another brand’s A2?
There is no enforced industry standard for A-sizes, so each brand grades its own pattern; measured charts are the only reliable comparison.
