How to size a BJJ gi you can't try on

The short answer: the method in four steps

Sizing a gi you can't try on comes down to a simple, repeatable process. First, find your height and weight. Second, pull up the specific brand's size chart and find the A-size that matches your height, then sanity-check it against your weight. Third, adjust for build if your proportions are unusual. Fourth, factor in shrinkage, sizing up slightly only if the gi is cotton and not pre-shrunk.

Follow those four steps in order and online buying stops being a roll of the dice. You're not hoping a size fits — you're matching your measurements to a chart, accounting for how the fabric will move after washing, and adjusting for your particular body. That's the difference between confidence and a return.

The rest of this guide walks through each step in detail, but if you remember nothing else: height first, the brand's own chart, then build and shrinkage. Our gi size finder automates the first pass so you have a starting size to verify.

Why A-sizing is height-first

BJJ gis use the A-scale — A0 through A5, with variants — and the single most important thing to understand is that it's driven primarily by height, then adjusted for build. This surprises people who expect gi sizing to track weight, the way clothing or weight classes do. It doesn't: two people at the same weight but different heights usually wear different A-sizes.

The reason is structural. A gi's jacket length, sleeve length, and pant length all key off your height, and those are the dimensions you can't easily fix after buying. Girth — how roomy the gi is through the body — is more forgiving, since a slightly loose or snug fit still works. So height sets your baseline size, and everything else is adjustment.

This is why sizing by weight alone is the classic online mistake. A heavy, short grappler who picks a large size by weight ends up with sleeves and pants far too long; a tall, lean one who picks a small size ends up with a gi that's too short to be legal or comfortable. Start from height and you avoid both traps.

Reading a brand size chart

Every reputable gi brand publishes a size chart mapping height and weight ranges to A-sizes, and reading it correctly is the core of online sizing. Find where your height falls, then check that your weight is within the range for that size. If your height and weight point to different sizes, height usually wins, because length is the harder dimension to fix.

The critical caveat is that charts differ between brands — there's no enforced standard, so an A2 in one brand is not identical to an A2 in another. This means you must use the chart for the exact brand you're buying, every time, and never assume your size carries over from a gi you already own. It's the most common source of sizing regret.

When you're between two sizes on the chart, don't guess — let build and shrinkage break the tie, which the next steps cover. And if a brand offers tall, slim, or half-sizes, use them: they exist precisely to solve the between-sizes problem for awkward proportions.

Adjusting for build

Once the chart gives you a baseline, adjust for your build. If you're tall and lean, a size that covers your height may be baggy through the torso — look for a slim or competition cut, or a brand known for trimmer fits. If you're short and muscular, a size that fits your build may be too long in the sleeves and pants — a shorter cut or a size down with room in the shoulders can work better.

The guiding principle for awkward builds is to prioritize the dimension that would be unwearable if wrong. Sleeves and pants that are too short can make a gi illegal for competition and uncomfortable to train in, whereas a bit of extra room in the body is merely cosmetic. When in doubt, protect length and accept some looseness.

Some brands sell jacket and pants separately or offer multiple cuts, which solves build problems neatly. If you're consistently hard to fit off the standard chart, seeking out those brands is worth more than any amount of size-chart agonizing over a maker that only offers one cut.

Planning for shrinkage

Shrinkage is the factor that turns a chart-perfect order into a gi that fits after a few washes — or one that's suddenly too tight. Cotton gis shrink, mostly from heat, so if a gi is 100% cotton and not pre-shrunk, many grapplers size up slightly and let it shrink into a good fit. If it's pre-shrunk, or you plan to wash cold and hang-dry, size to the chart instead.

The mistake is sizing up ‘for shrinkage’ on a pre-shrunk gi, which leaves you swimming in it. Read the product description carefully: if it says pre-shrunk, trust the chart; if it doesn't, expect a few percent of shrink with warm washes and drying and plan accordingly. This one detail resolves a huge share of online sizing complaints.

Our shrinkage calculator estimates how much a given fabric and wash routine will shrink, so when you're between sizes you can decide whether to size up with real numbers rather than a guess. Pair it with the size finder and the between-sizes dilemma largely solves itself.

The fit checks that matter

Knowing what ‘fits’ means lets you evaluate a gi even without trying it on, and later confirm you ordered right. Three checks cover it. The jacket lapel should cross comfortably with about a fist of room between your chest and the closed jacket. Sleeves should reach near your wrist bone with arms extended — IBJJF has rules about how far up the forearm a sleeve can sit, which matters for competition legality.

Pants should let you squat deeply without binding, with the cuffs resting around the top of the foot. If a gi passes all three checks, you have a good fit regardless of what the label says; if it fails one, especially on length, the size is wrong for you no matter how the chart read.

These checks are also your return-decision tool. When your gi arrives, run them before washing it. If it clearly fails on length, exchange it before you wash and shrink it into non-returnable territory. Which is why the next point matters.

Women's sizing and returns

Two practical notes round out online buying. First, women's sizing: look for brands offering dedicated women's cuts or F-sizes rather than forcing a men's A-size to work, since a men's cut is shaped for a different build and often fits poorly through the shoulders, chest, and hips even at the right length. Where a women's line exists, it's the single biggest upgrade to fit.

Second, check the retailer's return and exchange policy before you buy your first gi in a new brand. Because charts differ between makers, your first order from an unfamiliar brand carries the most sizing risk, and an easy exchange turns a genuine mismatch into a minor inconvenience rather than a write-off.

Crucially, don't wash a gi you're unsure about. Most retailers won't accept a washed gi for return, and washing also triggers shrinkage that changes the fit. Run your fit checks on the unwashed gi first, and only wash once you're confident it's a keeper.

Run your numbers

Put the method together: measure your height and weight, find your A-size on the specific brand's chart with height leading, adjust for your build, and factor shrinkage — sizing up only for cotton that isn't pre-shrunk. Confirm the fit with the fist test and sleeve and pant length when it arrives, before washing. That's a complete online-sizing system with the gambling removed.

Start with our gi size finder for your baseline A-size and the shrinkage calculator if you're between sizes. For the specific brand-and-build questions the community asks most, our gi sizing questions answered covers the common edge cases. Do this and ordering a gi online becomes about as reliable as trying one on.