What Size Is a Youth Medium? A Sizing Guide for Team Orders

Short answer: a youth medium fits roughly a 27 to 28 inch chest, on an athlete around 50 to 53 inches tall — typically an 8 to 10 year old. It is not the same as an adult extra small, and it is definitely not the same as an adult small.

That last part is where most team orders go wrong. Youth and adult sizing are two different pattern families, not one ladder with small numbers at the bottom. Here's how the sizes actually map, and how to collect them for a roster so every jersey that arrives fits the athlete it was ordered for.

Youth sizes in real measurements

Every brand cuts a little differently, so treat this as the typical range rather than gospel. For the exact numbers on a specific garment, check our sizing charts — we publish them per style, because a trail jersey and a full-button baseball jersey don't fit the same way even in the same nominal size.

Age is the least reliable column on that table. Two twelve-year-olds on the same roster can be four inches apart in chest measurement. Use it to sanity-check a submission, never to place an order.

Is a youth XL the same as an adult small?

No, and this is the single most expensive misunderstanding in team apparel.

The chest measurements are close enough to fool you — a youth XL lands around 31 to 33 inches, an adult small around 34 to 36. Close enough that a parent looking at a chart might round either way. But chest is only one of three measurements that decide whether a jersey fits.

The adult small runs two to three inches longer through the torso. It's also cut wider at the shoulder point, with the armhole dropped lower and the sleeve set at an angle built for a grown frame. Put that garment on a thirteen-year-old and the shoulder seam slides down the arm, the armhole hangs below where their arm actually pivots, and the hem sits past the hip.

That extra length isn't room to grow. It's fabric bunching at the waist, and on a pitcher extending through a throw or a rider standing on the pedals, it's in the way.

A true youth pattern is drafted around a younger athlete's proportions: shorter body, narrower shoulder, different sleeve geometry. When a supplier takes an adult block and runs it through a reduction formula, the numbers shrink and the proportions stay wrong. Our youth line is patterned separately for exactly this reason — the Devo jersey isn't a small adult jersey with a different label on it.

When you're comparing suppliers, ask the question plainly: is your youth sizing a dedicated pattern, or scaled adult sizing? A supplier who can describe the difference in shoulder width and torso length is telling you something. One who says "yes, we carry youth sizes" is telling you something too.

How to measure, so you only do this once

Three measurements cover almost every garment we make:

Chest. Around the fullest part, under the arms, tape level all the way around and snug but not pulling. Arms down.

Height. Shoes off, back to a wall.

Torso length matters for jerseys that need to stay tucked. Measure from the top of the shoulder at the neck, straight down to where they want the hem to sit.

Take them over a t-shirt, not a hoodie. A parent measuring a kid in a winter layer will consistently order a size too big, and you won't find out until distribution day.

Getting sizes off a full roster

The measuring is the easy part. Collecting thirty of them is the job nobody signed up for.

Send the chart with the request, not after it. Not "let me know if you need the sizing info." Attach it, or link it, in the same message. When families are looking at real numbers while they answer, they measure instead of guessing from the last t-shirt they bought.

Ask for a measurement, not a letter. "Chest: 28 inches" is data you can act on. "Medium, I think" is a coin flip, and it's wrong often enough to matter. A player who lives in one brand has a completely different mental model of medium than a player who lives in another, and custom apparel is patterned differently from either.

For youth programs, ask parents to measure fresh. Kids move a full size in an offseason. Last season's order is not a reliable source, and neither is the number on the tag of a shirt that's been through forty washes.

Use a form, not the group text. A form with required fields returns a name and a number. A text thread returns forty messages you have to reconcile at 11pm.

If you'd rather not run the collection at all, that's the reason we build a store for every program: each athlete or parent picks their own size at checkout, so the person who knows the body submits the number. There's no transcription step, which is where most sizing errors are actually born. You can see how a store works before committing to anything.

Should you size up for growth?

Sometimes, and it's a real trade-off rather than free insurance.

Sizing up works when the jersey is loose-fitting by design, when the season is long, or when you're outfitting a program that reissues gear year to year. A slightly big trail jersey in September is still wearable in May.

It works less well on anything cut close to the body. A bib short, a skinsuit, a tri suit or a fitted competition jersey is designed to sit against the body, and it performs the way it's meant to at true size. On those, order what fits now.

The middle path most programs land on: order true-to-measurement for fitted pieces, and size up only where the athlete is within an inch of the top of a range and clearly growing. Tell families which of those you're doing, so nobody's surprised.

Common questions

What age is a youth medium?

Usually 8 to 10, but treat that as a starting guess and confirm with a chest measurement. Age is the loosest predictor of fit on the chart.

What is youth medium in adult sizes?

There isn't a clean conversion, which is the honest answer. A youth medium is roughly 6 to 8 inches smaller in the chest than an adult small and several inches shorter in the body. If an athlete is between the two, measure — don't convert.

Is youth large the same as adult XS?

Closer than youth XL to adult small, but still not the same cut. Youth large runs around 29 to 30 inches in the chest with a proportionally shorter torso. If your supplier offers a real youth large, that's usually the better fit for a 12-year-old than an adult XS.

What if an athlete falls between two sizes?

Go up for loose-fit garments, down for fitted ones. If it's a fitted piece and they're genuinely between, ask for a sample before you commit the whole roster.

Do you have to order the same size range for the whole team?

No. A single order can run youth and adult sizes together — that's normal for programs spanning multiple age groups, and it's a good test of whether a supplier actually carries both pattern families or just relabels one.

If you're pulling together a roster order and want a hand mapping sizes to the styles you're looking at, send us the details and we'll work back from your season.