What Is a Size Run? A Strategic Guide to Sizing Ratios for Clothing Brands
Every clothing brand eventually faces the same high-stakes moment: you have a design you are excited about, a factory quote in hand, and then the manufacturer asks — "What's your size run?"
If your answer is a confused silence, this guide is for you. Mastering the Size Run is not just a logistics detail; it is one of the most critical capital allocation decisions you will make in the apparel supply chain.
1. Defining the "Size Run"
In garment manufacturing, a Size Run is the specific breakdown of units you order for a single style. it tells your factory exactly how many units to produce in each size to meet your total order quantity.
For example, if you are placing a Bulk Order for 300 hoodies, a standard size run distribution might look like this:
| Size | % of Run | Units |
|---|---|---|
| XS | 5% | 15 |
| S | 20% | 60 |
| M | 30% | 90 |
| L | 25% | 75 |
| XL | 15% | 45 |
| XXL | 5% | 15 |
| Total | 100% | 300 |
While the theory is simple, getting these ratios wrong is one of the most expensive mistakes a new brand can make.
2. Why Size Run Ratios Matter More Than You Think
Bad size run planning leads to two painful, margin-killing outcomes:
- Dead Inventory: Over-ordering extreme sizes (like XXS or XXL) because you "guessed." Every unsold unit represents capital tied up in a warehouse that you will never recover.
- Stockouts in Core Sizes: Under-ordering Mediums or Larges because they seemed "boring." You sell out in week two, leaving hundreds of customers empty-handed and buying from your competitors instead.
Expert Solution: Avoid the guesswork. Use our Free Size Run Planner to instantly calculate your distribution with built-in inventory risk alerts.
3. Standard Size Runs by Market
There is no universal "right" size run. Body size distributions vary significantly by region. Here are the benchmark distributions used by most global manufacturers:
North America (US / Canada)
- Best for: Tops, T-shirts, Hoodies, and Unisex Streetwear.
- Trend: Medium and Large dominate, typically accounting for 55% of a typical North American run.
Europe (EU / UK)
- Trend: Sizing skews slightly smaller and more evenly distributed than in North America, with a higher weight toward XS and Small.
Asia (CN / JP / KR)
- Trend: Sizing skews significantly smaller. XS and Small together can represent 40–50% of a total production run.
4. The MOQ Trap: Per-Style vs. Per-Size
Most new brands fall into the per-size MOQ trap. If your factory sets a minimum of 30 units per size, you are forced to order 30 XS and 30 XXL even if your data suggests you will only sell 5 of each.
Before committing, ask your factory explicitly: "Is your MOQ per style or per size?" Budgeting for dead inventory at the extremes is a necessity if you cannot negotiate these per-size minimums down.
5. How to Plan Your Size Run: Step-by-Step
- Confirm Factory MOQs: This is your "floor." Work backward from these constraints.
- Choose a Benchmark: Use the tables above based on your target market.
- Adjust for Fit: Unisex styles typically skew toward M/L, while "slim-fit" items may require higher counts in larger sizes.
- Validate with Data: If you have even 20 past orders or pre-order results, use that real-world signal over any industry benchmark.
- Run the Numbers: Use a dedicated tool like the Topology Size Run Planner to calculate units and flag high-exposure sizes (any size exceeding 25% of your total run).
The Bottom Line
A Size Run is a capital allocation decision. Planning a thoughtful distribution from the start is one of the highest-ROI habits a young clothing brand can build.
Topology is a manufacturing partner for independent brands. We help founders navigate everything from first samples to full production runs. Get in touch if you are planning your first order.
How the Size Run Planner Works
Our tool is designed to take the manual math out of your supply chain planning:
- Market Intelligence: Select from North America, Europe, Asia, or Australia to apply localized sizing curves.
- Risk Detection: The algorithm flags "High Exposure" sizes (where overstock risk is high) and "Watch MOQ" alerts (where your quantity might be too low for factory standards).
- Custom Ratios: For brands with established data, the "Custom" mode allows you to set your own percentages while the tool handles the unit conversions and rounding.
For a complete overview of apparel sizing and grading, see our complete sizing guide for brands.
Frequently Asked Questions (FAQ)
1. What is the most common size run ratio for start-up brands? For North American markets, a standard entry-level ratio is often 1-2-2-1 (e.g., 1 Small, 2 Medium, 2 Large, 1 XL). This focuses inventory on core middle sizes where the majority of customer demand exists.
2. Should I order the same quantity for every size? No, ordering an equal distribution (e.g., 50 units of every size) is a common mistake that leads to "dead stock" in extreme sizes and "stockouts" in core sizes. Always use a weighted distribution based on your target market.
3. What is a "Per-Size MOQ"? A Per-Size MOQ is a factory requirement that sets a minimum production limit for each individual size (e.g., at least 30 units per size), rather than just a total minimum for the entire style.
4. How do I adjust my size run for unisex garments? Unisex styles typically require a shift toward the larger end of the spectrum (Medium and Large) because the average male build is larger than the average female build. Small and XS sizes often move slower in unisex collections.
5. When should I update my size run data? Your first size run is a hypothesis. You should update your ratios after every production cycle by analyzing real sell-through data to ensure your next order is more capital-efficient.