There's no universal sizing standard across BJJ gi brands. An A2 from one brand can fit like an A1 from another, and the labeling systems themselves aren't consistent — some use A0 through A5, others use S/M/L, and some use F1–F4 for their "female fit" or "feather weight" lines. Buying based on the size you wear in one brand almost never guarantees the same fit in another.
How to measure yourself first
Before comparing brand charts, get three measurements with a soft tape measure:
- Height — most sizing charts sort primarily by height range.
- Weight — the secondary factor; two people the same height with different builds often need different sizes.
- Wingspan (fingertip to fingertip, arms out) — the measurement most people skip, and the one that determines whether the sleeves will be legal length for competition (sleeve must not extend past the wrist bone when the arm is fully extended).
General size range by height
| Height | Common size label |
|---|---|
| 5'2" – 5'5" | A1 |
| 5'5" – 5'8" | A2 |
| 5'8" – 5'11" | A3 |
| 5'11" – 6'2" | A4 |
| 6'2"+ | A5 |
This is a starting point, not a guarantee — always cross-check against the specific brand's own chart, since cut and shrinkage tolerance vary.
Why the same letter-number doesn't mean the same fit
Two factors cause the most sizing confusion between brands:
- Pre-shrunk vs. non-shrunk fabric. A "pre-shrunk" gi should fit close to true-to-size after washing, while a non-pre-shrunk gi is cut larger to account for shrinkage — buying the same letter size across both types leads to very different final fits.
- Cut philosophy. Some brands cut athletic/slim fits as their standard, others cut a more traditional boxy fit. A slim-cut A2 can fit noticeably tighter through the shoulders than a traditional-cut A2, even at the same height range.
When ordering a new brand for the first time, check the brand's return policy before buying rather than after. Sizing mismatches are common enough that reputable BJJ gear brands almost always have a straightforward exchange process — but only if you check before the tags come off.
Kids' sizing works differently
Kids' gis are typically sized by age range (M0 for roughly ages 4-6, M1 for 7-9, and so on) rather than height alone, since younger practitioners vary less in height but still need room to grow. It's common to size up slightly for a kids' gi specifically because of how often growth outpaces gi replacement.
The most reliable approach, regardless of brand: measure once, keep those three numbers saved somewhere, and check them against each brand's specific chart every time — rather than assuming your size in one brand transfers to the next.