Definition
A size run is the full set of sizes you order for a garment plus the quantity you take in each one. It is the difference between ordering 200 hoodies and ordering 15 XS, 40 S, 55 M, 50 L, 30 XL and 10 XXL. Get the size run right and almost every piece finds a wearer. Get it wrong and you are left with a box of XXL nobody asked for.
Definition
A size run, also called a size curve or size breakdown, describes how one order is split across the available sizes. It has two parts: the size range you offer, and the depth in each size. A 300-unit t-shirt order might run XS to 3XL with a curve of 10 / 35 / 70 / 85 / 60 / 25 / 15. That curve is your size run. Suppliers quote against it, warehouses stock against it, and fulfilment picks against it.
How a size run works
Most size runs start from a standard bell curve. Demand clusters in the middle sizes, so M and L usually carry the largest share, with S and XL either side and the extremes taking a thin slice. A common European starting point for a mixed adult audience is roughly 5% XS, 15% S, 25% M, 25% L, 18% XL, 8% XXL and 4% 3XL. That curve is a hypothesis, not a fact.
Three things move the curve. Audience is the biggest one. A tech company with a male-skewed engineering team runs heavier on L and XL, while a beauty brand gifting its community runs heavier on S and M. Fit is the second. An oversized hoodie pulls demand down a size, because people who normally take L will happily take M. Country is the third. The same style ordered for a US office and a Japanese office needs two different curves.
The trade-off sits between coverage and waste. A wide size run with deep stock in every size means nobody gets left out, but it ties up budget and creates slow-moving inventory. A narrow run keeps cash free and reduces leftovers, but it excludes people, which defeats the point of merch. Most teams land somewhere in between: full range, shallow depth at the ends. 2XL and above often carry a surcharge, since they use more fabric. Budget for it before you approve the order.
Size run in branded merch
- Onboarding kits and employee gifting. Collect sizes at signup instead of guessing. Knowing the real distribution of your team means the size run matches it almost exactly and replenishment stays small.
- Event and conference apparel. You cannot poll a crowd in advance, so lean on a standard curve weighted toward the middle, and carry a few extra XL and XXL. Running out of large sizes at a booth is the failure people remember.
- Retail-style merch stores. In an internal merch shop, the size run becomes an inventory decision. Stock the middle deep, keep the ends thin, and use production data from the first drop to correct the curve on the reorder.
A size run is the breakdown of an apparel order by size, showing which sizes are included and how many units are ordered in each.
5 tips to elevate your Size run strategy
| Tip | Steps |
|---|---|
| Ask before you order | Run a two-minute size survey. Real data beats any standard curve for a known group. |
| Round up, not down | When a calculated size sits between two units, take the extra piece in the larger size. Oversized is wearable, undersized is not. |
| Check the surcharge | Confirm the price step for 2XL and above so your per-unit budget holds. |
| Order the ends shallow | Keep XS and 3XL in the range for inclusivity, but only a handful deep to avoid dead stock. |
| Record what you shipped | Log the size run and leftovers so the next order starts from evidence. |
Key Terminologies
Frequently Asked Questions
What is a typical size run for t-shirts?
A common adult unisex curve is roughly 5% XS, 15% S, 25% M, 25% L, 18% XL, 8% XXL and 4% 3XL. Adjust it based on your audience, since a male-skewed group shifts demand toward L and XL.
What is the difference between a size run and a size chart?
A size run is how many units you order in each size. A size chart lists the body and garment measurements for each size. One is a quantity decision, the other is a fit reference.
Do I have to order every size?
No, but a narrow range excludes people. Most brands keep the full range from XS to 3XL and simply order very few units at the extremes to balance inclusivity with inventory cost.
Does an oversized fit change the size run?
Yes. Oversized and relaxed cuts pull demand down roughly one size, so you can shift weight from XL and XXL toward M and L. Always confirm with the garment measurements before committing.
How do I avoid leftover stock from a bad size run?
Survey your recipients before ordering, keep the extreme sizes shallow, and record what actually shipped. Use that data to correct the curve on your next production run.
