You can ship a 5K weekend with the wrong shirt order in two ways. You can underorder and run out of larges by Saturday morning. You can overorder and store 80 shirts in your garage until next year, where they will sit until you find them again the week before the next race.
Both happen constantly. The fix is not complicated, but it does require three numbers most race directors do not have at their fingertips.
Why 85 percent, not 100
Two reasons. First, registration data lies. Some of those registrants will not show. Cold-weather races lose 8 to 15 percent. Charity walks built around team captains lose 15 to 20 percent. Hot-weather races held mid-summer lose less because the people who registered really wanted to be there.
Second, you do not have to give a shirt to every registrant on race day. Plenty of races mail late registrants a shirt the following week. That moves the inventory pressure off the day-of tent and onto a slower, calmer week of address-collection emails. If your registration platform can export shipping addresses, this is the quiet answer.
How to set the size distribution
Start with the base distribution above. Then nudge it on three signals:
- Audience skew. Women-skewing race? Move 5 to 10 percent from XL/2XL into S/M. Men-skewing endurance event? Reverse it. Mixed family 5K? The base is fine.
- Cut. If you are using women's-cut shirts in addition to unisex, you need to ask the registration form which the runner wants. Do not guess. The unisex small fits a women's medium, and nobody is happy when you guess for them.
- Late additions. Sponsors, board members, and the race director's family always need a shirt. Add 15 shirts to the order before you do anything else, distributed L/XL/XL.
The order-side timeline
For a typical 200 to 800 registrant 5K, this is the order-side timeline that does not require panicking:
| Week | Action |
|---|---|
| T-10 | Confirm shirt vendor, pick fabric (cotton, blend, or tech tee), lock decoration method. |
| T-8 | Send art proof. |
| T-6 | Open the size collection question on registration. Make it required. Add a visible size chart. |
| T-4 | Pull current registrant counts and lock the order. Apply the distribution above to the count, plus your 15-shirt buffer for sponsors and family. |
| T-2 | Shirts arrive. Inspect 5 percent for misprints. Box by size for race-day distribution. |
| Race week | Walk-up registrants get a "we will mail it" card. |
What to do with leftovers
Do not throw them away and do not let them haunt your storage closet. Three options that actually work:
- Donate to the charity beneficiary. Shelters, scholarship orgs, and youth programs will take them.
- Post a Friday "leftover sizes" email to the runner list at half price for next year's pre-registration.
- Use them as crew shirts for next year's volunteers.
Tech tee or cotton
If you can afford a tri-blend or basic tech tee, get one. Runners wear them again. Cotton race shirts get cleaning rags within 30 days. You are not buying a shirt, you are buying the chance the runner remembers your race the next time they sign up for one. That said, a $4 cotton crew with a clean design beats a $9 tech tee with a busy logo block. Design quality matters more than fabric. Aim for both. Settle for neither at the cost of the other.
Plug in registrant count, audience skew, and weather risk. Returns a per-size order with the buffer baked in.
Pick the right shirt for the budget
Race director budgets vary wildly, from "we have a $400 youth fun-run sponsor" to "we are spending $9,000 on a corporate-sponsored 10K." The shirts that perform across that range:
Recommended starting points
3 picksOnce you have a working count and a fabric pick, the next decision is the design itself. Keep it readable from across a parking lot, keep the sponsor logos legible at one yard, and keep the back simple. The fewer ink colors, the lower the price-per-shirt, and the less likely the registration fee runs over budget.