Buying your first BJJ gi is one of those "how hard can it be?" moments that turns into "why doesn't this fit?" real fast.
Gi sizing isn't standard across brands. A Kingz A2 fits differently from a Hayabusa A2. Add shrinkage from the first wash and it's easy to end up with sleeves that stop at your forearms.
Here's how to nail it first try.
How Gi Sizing Works
Most BJJ gis use a letter-number system:
| Size | Typical Height | Typical Weight |
|---|---|---|
| A0 | 150–160 cm | 45–55 kg |
| A1 | 160–173 cm | 55–70 kg |
| A2 | 173–185 cm | 70–85 kg |
| A3 | 183–193 cm | 85–100 kg |
| A4 | 190–200 cm | 100–115 kg |
| A5 | 195+ cm | 115+ kg |
Some brands add "L" (long) and "H" (heavy) variants:
- A2L — same width as A2 but longer sleeves/pants. For tall, lean builds.
- A2H — same length as A2 but wider in the chest and waist. For broader builds carrying more weight at that height.
Women's gis use "W" sizing (W1, W2, etc.) with cuts designed for female proportions — narrower shoulders, wider hips, shorter torso relative to leg length. More on this below.
How to Measure Yourself for a Gi
You need two numbers:
- Height — barefoot, against a wall
- Weight — honest morning weight (the gi won't hide anything)
- Between A1 and A2? Go A2 and shrink it. Gis don't stretch — they shrink. Always size up if you're borderline.
- A2 too wide, A2L too narrow? Go A2L and shrink the width slightly with hot wash cycles. Better to have extra length you can shrink than short sleeves you can't fix.
- Broad shoulders, not tall? Look at "H" (heavy) variants if the brand offers them. Alternatively, size up and shrink the length aggressively.
- Cold wash, line dry = minimal shrinkage. Do this if the gi fits perfectly out of the bag.
- Warm wash, tumble dry low = moderate shrinkage. Good for taking in a slightly loose gi.
- Hot wash, hot dry = maximum shrinkage. Last resort for a gi that's genuinely too big. Don't do this unless you need to — you can't undo it.
- Narrower shoulders and wider hip-to-waist ratio
- Shorter jacket length relative to sleeve length
- Tapered pant cut
- Sleeves should reach your wrist bone when arms are extended forward (not hanging down)
- Lapels should overlap by at least 10cm across the chest
- You should be able to pinch 2–3cm of fabric at the bicep
- The skirt (bottom of the jacket) should cover your belt
- Cuffs should sit at the ankle bone, not drag on the floor
- Drawstring should cinch without cutting in
- Knees should have room to bend without the fabric pulling tight
- If the gi rides up constantly, it's too small
- If your training partner can grab fistfuls of loose fabric at the sleeves, it's too big
- Ideal = your partner can make grips but the fabric isn't baggy
That's the baseline. The size chart above will get you 80% of the way there.
If you're between sizes, the decision tree:
Brand Sizing Differences
This is where beginners get tripped up. Not all A2s are created equal.
| Brand | Fit Characteristic |
|---|---|
| Kingz | Athletic cut. Trim through the body, roomy in the shoulders. True to size chart. Minimal shrinkage. Our most-stocked gi brand. |
| Bad Boy | Classic fit. Slightly roomier than Kingz in the same size, good for broader builds. Durable construction, solid entry-level option at a great price point. |
Rule of thumb for your first gi: buy a Kingz in your chart size — they are the most consistent fit and we stock the widest size range. If you are on a tighter budget or have a broader build, the Bad Boy Focus Gi is a solid alternative at $119.95.
Shrinkage: What to Actually Expect
All gis shrink to some degree. The question is how much.
Pre-shrunk gis (most modern gis): Expect 2–4% shrinkage across the first 2–3 washes. On a 170cm sleeve, that's roughly 3–7cm. Barely noticeable.
Non-pre-shrunk gis (less common now, some traditional weaves): Expect 5–8% shrinkage. This is why you size up. A non-pre-shrunk A2 might end up fitting like an A1.
How to control it:
Never: soak a brand new gi in hot water for hours. You'll destroy the collar and warp the weave. Gradual shrinkage over multiple washes is the safe approach.
Women's Gi Sizing
Women's gis are cut differently — not just smaller versions of men's gis. The key differences:
Most brands convert like this:
| Women's Size | Rough Men's Equivalent |
|---|---|
| W1 | A0 |
| W2 | A1 |
| W3 | A1L or A2 |
| W4 | A2 or A2L |
But size charts are more important here than for men's gis. Use the brand's specific chart. If you're built athletically (broader shoulders from cross-training or previous sports), you might prefer a men's A1 or A2 over a women's cut.
Kids' Gi Sizing
Kids' gis use "M" sizing (M0, M1, M2, etc.) and are based almost entirely on height, not weight. Most kids' gis have elasticated waists and cinch cords, so the fit is adjustable.
| Size | Height |
|---|---|
| M0 | 100–115 cm |
| M1 | 115–130 cm |
| M2 | 130–145 cm |
| M3 | 145–160 cm |
Kids grow. Buy slightly big and cinch it. A gi that's a little roomy today fits perfectly in 3 months. A gi that fits perfectly today is unwearable by the next grading.
The Fit Test: How to Know It's Right
Once the gi is on and tied:
Jacket:
Pants:
After rolling:
One Gi vs Two: The Honest Math
If you train once a week: one gi is fine. Wash it after every session, hang dry overnight.
If you train 2–3 times a week: buy two. You'll be washing every other day anyway, and having a dry gi ready means you're not rushing a damp one into your gym bag (which is how gis develop that permanent funk).
If you train 4+ times a week: two gis minimum, ideally a third in rotation. At this volume, your gis are consumables — expect to replace them every 12–18 months regardless of quality.