The problem with guessing
Size splits are where first-time orders quietly go wrong. Guess flat, ten of every size, and you run out of L while a box of XS gathers dust. The fix isn't complicated: either use a proven curve, or collect real sizes when the group is small enough to ask. The cost of getting it wrong scales with the run: on a senior class order like Whitney High School's Class of 2027 tees, a curve that skews one size too small leaves shirts nobody wears.
The standard curve
For a general adult group in the US, the following is a provisional planning curve, not a forecast:
- S: 10 to 15%
- M: 25 to 30%
- L: 25 to 30%
- XL: 15 to 20%
- 2XL: ~10%
- XS and 3XL: a few of each once the run passes ~50 pieces, or on request.
With the general-adult curve and no extra buffer, the calculator below splits 50 shirts as XS 1, S 6, M 14, L 14, XL 10, 2XL 4, and 3XL 1. The workspace uses a separate default curve with more extended-size coverage, including 4XL, so its estimates can differ. Treat either curve as a starting point and adjust for your audience, fit, available garment sizes, and any sizes already collected.
Example size breakdowns for 50, 100 and 250 shirts
These examples use the quick calculator’s general-adult curve, with no extra buffer and all seven sizes available. Each column adds up to the stated order total. Replace estimates with collected sizes wherever possible, and check the selected garment’s actual size range before ordering.
| Size | 50 shirts | 100 shirts | 250 shirts |
|---|---|---|---|
| XS | 1 | 3 | 7 |
| S | 6 | 13 | 32 |
| M | 14 | 27 | 68 |
| L | 14 | 27 | 68 |
| XL | 10 | 19 | 48 |
| 2XL | 4 | 9 | 22 |
| 3XL | 1 | 2 | 5 |
Planning for a known club or a mixed event? Read the school and club ordering guidance or the hackathon planning guide before deciding how many spares to add.
This quick calculator adds the flat percentage you select. Planning several groups, giveaways or a CSV? Use the full merch size calculator for item-specific spares and pack rounding. Its recommended spares turn 100 people into 108 shirts, while 5% in the quick calculator gives 105.
When to bend the curve
- Student groups: use collected sizes when available. The student option is a provisional curve, not a rule about your group’s bodies or preferences.
- Oversized and drop-shoulder blanks: compare the actual measurements and intended fit. Do not automatically move everyone down a size.
- Mixed-audience events (conferences, launches) benefit from a provisional curve and spares. Use the full calculator for its recommended spare quantity, then check the split against your audience.
- Resale drops should follow your audience data if you have any; if not, the curve above is the standard starting point.
Under ~30 people? Just ask
For a team, club, or onboarding kit, collecting real sizes beats any curve. A one-question form gets it done, but send the size guide along with it: letter sizes vary between styles, and flat garment measurements compared against a shirt someone already owns is the only reliable check. This matters double for oversized fits, where the style guide explains how each cut runs. Size runs differ by garment too: browse the wholesale blank catalog to compare fits, or start from custom t-shirts and custom hoodies, where the curve skews differently.
Lock it in on the quote
Size splits are part of every written quote, so you don't have to get this perfect alone: send your headcount or collected sizes with the quote request for exact pricing, or get help choosing if you are still deciding on the garment or size split. We sanity-check the curve before production. Ordering for a club or class? The club merch playbook covers the whole flow from size collection to delivery.