For a group where everyone is guaranteed a shirt (staff, a work crew, a paid team roster), order your exact headcount plus 8 to 10 percent for exchanges and the person who signs up late. For an opt-in event where not everyone who registers actually wants a shirt, like a fundraiser or a charity run, order 85 to 90 percent of your registration count instead. Getting that total right only solves half the problem. The size breakdown is what actually determines whether you end up with a box of leftover larges three weeks after the event.
"How many shirts do I order for this event" is one of the first questions we get at Conquer Printing most weeks, and the honest answer depends on who's showing up. A Sacramento contractor putting a dozen guys in matching hi-vis shirts already knows every size on the crew. A school PTO across town trying to guess sizes for 300 kids they've never measured does not. The math is different for each of them, but the mistake is the same: order a flat number, split it evenly across sizes, and end up reordering a month later at a worse price because the new run is too small to hit a good rate.
Start with the right base number
Skip the instinct to round up "just in case." A vague buffer either leaves you short or buries you in shirts that sit in a closet until next year. Use the event type to pick your buffer instead of guessing:
| Event type | Base number | Buffer |
|---|---|---|
| Staff or crew apparel (mandatory) | Exact headcount | Add 5 to 8 percent for exchanges and new hires |
| Corporate event, all attendees confirmed | Confirmed RSVP count | Add 8 to 10 percent |
| Fundraiser or charity run (opt-in) | Registrations or expected sign-ups | Order 85 to 90 percent of that number |
| School spirit wear, pre-sale by size | Actual pre-orders collected | Add 3 to 5 percent for late orders only |
| Vendor booth giveaway or trade show | Expected foot traffic | Order 20 to 30 percent of expected visitors |
If you're setting up at a Sacramento farmers market or a fall trade show and giveaway shirts are part of the pitch, that last row is the one to plan around, since foot traffic almost never converts to takers one for one.
Notice the fundraiser row runs lower than the others. Registration numbers for a run or a walk almost always include people who paid, then decided not to pick up merchandise, or who ordered a shirt for someone who backed out. Boosterthon's own guide to ordering event and spirit wear shirts for schools makes the same point: treat your registration count as a ceiling, not a target.
Get the size ratio right, or the total won't matter
Adult sizing on a mixed group (not all men, not all kids) tends to follow a predictable curve. A reasonable starting split for a general adult crowd looks like this:
- Small: 10 to 12 percent
- Medium: 25 to 28 percent
- Large: 30 to 32 percent
- Extra large: 20 to 22 percent
- 2XL and up: 10 to 13 percent
That's a starting point, not a rule. A construction crew skews heavily toward large and extra large. A school fundraiser skews toward youth and small adult. If you already know your group, adjust the ratio before you order rather than after. Gildan's official size chart is worth a look if you're deciding between a standard fit and a heavier build, since chest measurements shift more between sizes on some styles than people expect.
When guessing the ratio is the wrong call
If you can collect sizes ahead of time, do it. A PTO running a spirit wear sale, a company issuing uniforms to a known staff list, or a wedding party with RSVPs all have the option to pre-sell or pre-survey by size. When that's possible, skip the ratio table entirely and order exact counts. Guessing is a fallback for events where you genuinely can't collect that data in time, like a festival giveaway or a fun run with a shirt included in the registration fee.
What it costs when you order too few
This is where a lot of people get burned. Screen printing has a setup cost baked into the price of the first run: the screens have to be made before the first shirt gets printed. Order 150 shirts and the setup cost spreads out across all of them. Run out and go back for 20 more a month later, and that same setup cost gets divided across a much smaller batch, so the per-shirt price on the reorder is often noticeably higher than what you paid the first time. We've written more about how that math works in our post on screen printing order minimums.
If there's a real chance you'll need a small top-up order later, or your headcount is genuinely unpredictable, DTF transfers are usually the better call for that piece of the order. There's no screen setup to amortize, so a reorder of 15 shirts costs close to the same per unit as a reorder of 150. It's the same reason we point people who want to test a design in small batches toward our DTF and DTG page instead of committing to a full screen printing run on a design they haven't sold yet. Screen printing still wins on price once your order gets big enough, but where that line sits depends on your design and shirt style, so run both options through the screen printing page and our quote tool before you decide.
A few sizing and ordering mistakes worth naming
Most of the trouble we see comes down to the same handful of habits, and it's worth naming them plainly instead of dressing them up:
Ordering everyone a medium because it "fits most people" doesn't work. It fits almost nobody well. Splitting the order evenly across five sizes ignores the actual curve of how bodies are distributed in a group, and you'll end up short on large and extra large every time. And treating a registration count as a hard order number, instead of a ceiling, is the single most common reason nonprofits end up with a garage full of shirts after the event.
Common Questions
How many shirts should I order for a 50-person event?
If every one of the 50 people is guaranteed a shirt, order 54 to 55: the headcount plus an 8 to 10 percent buffer. If it's an opt-in event where 50 people registered but attendance isn't confirmed, order 42 to 45 instead. Split those across sizes using the standard ratio unless you already know the group skews younger, older, or heavily toward one gender.
What's a normal t-shirt size ratio for a group order?
A workable starting ratio for a general adult group is about 10 percent small, 27 percent medium, 30 percent large, 21 percent extra large, and 12 percent 2XL and up. Adjust it based on who's actually in the group. A youth sports team or school fundraiser needs youth sizes built into that ratio, not adult smalls standing in for them.
Is it cheaper to order extra shirts now or reorder later?
Almost always cheaper to order extra now, at least for screen printing. The screens are already made and the press is already set up for your design, so adding 10 or 20 more shirts to the original run costs far less per piece than coming back in a month for a small reorder that has to cover the setup cost on its own. If you genuinely don't know your final count yet, ask about splitting the order between a screen printed base run and a DTF top-up.
Do I need an exact headcount before I request a quote?
No. Conquer Printing's online quote calculator will give you real pricing on a range of quantities in a couple of minutes, so you can compare a 100-shirt order against a 125-shirt order before committing to either one. Bring us your best estimate and we'll help you land on a final number that matches your budget and your actual group.
What if my group has a lot of big-and-tall or youth sizes?
Say so up front. Extended sizes and youth sizes usually carry a small per-unit difference from standard adult sizing, and getting that built into the quote from the start avoids a surprise later. If you're not sure how your group breaks down, reach out to us directly and we can walk through it with you before you place the order.
Bottom line
If you only take one thing from this: stop rounding up a flat number and splitting it evenly across sizes. Pull your real registration or headcount, apply the right buffer for your event type, and weight the sizes toward large and extra large unless you know your group runs differently. Then take that estimate, rough as it is, and run two or three quantities through our quote calculator side by side. Seeing the actual per-shirt price at 100 versus 125 versus 150 will tell you more about the right number than any ratio table, ours included.