Size Ratios for a First Order: The Short Answer
If you are a founder about to place a first production order and the factory asks how many of each size, the safest answer is a curve with a fat middle and thin ends, adjusted for who your customer really is. Size ratios are the proportions in which you split an order across sizes, and a first order is always an informed guess. The goal is not to be right, it is to be wrong cheaply and learn fast.
A good first split comes from four inputs: your audience, the fit of the garment, the category and any evidence you already have, such as pre-orders, a waiting list or sales from a smaller run. Sensible size ratios also respect what the factory can actually produce per size, colour and style.
Quantity limits are the other half of this planning, and they are explained in our guide to what MOQ means in clothing manufacturing. Read both before you finalise a purchase order.
What Are Size Ratios and a Size Curve in Clothing?
A size ratio is the share of an order allocated to each size. A size curve is the same idea drawn as a shape: how many pieces sit at XS, S, M, L and XL, and how steeply the numbers rise and fall. A bell shape, centred on the sizes your customers wear most, is the usual starting point for a general adult range.
Why your audience changes the curve
The curve is not universal. A brand for tall, broad-shouldered customers will sell more at the top of the range than a brand aimed at petite buyers. A streetwear label with an oversized fit may find customers choosing a size down. A workwear or club order may be shaped by the real headcount. There is no industry-standard curve to copy, which is why published splits should be treated as examples, not rules.
Why fit matters as much as audience
A fitted garment pushes customers to their true size, while a relaxed or oversized garment lets many people buy a size smaller or larger. If your size chart and fit are different from the competition, copying their split can mislead you. Our guides to the UK clothing size chart and to grading and size charts explain how the range itself is built.
How to Build Size Ratios From First Principles
You can build a first split in an afternoon with the steps below. None of them needs sales history, though any history you have should override the defaults. Write down your reasoning at each step, because that record is what you will review when the first sales data arrives.
Building a first size split
- 1Define the customerWho are they, how tall, how broad, and what do they wear in similar garments?
- 2Choose the rangeDecide which sizes you will offer. A shorter range makes each size run bigger.
- 3Set the centrePick the one or two sizes you expect to sell most and give them the largest share.
- 4Taper the endsAllocate smaller shares to the smallest and largest sizes. Do not leave them at zero.
- 5Check the factory rulesTest the split against minimums per size, colour and style, then adjust.
- 6Record your assumptionsWrite the reasoning down so you can compare it with sell-through later.
A planning method, not a formula. Treat the first split as a hypothesis you will test.
Step five is where many first splits change. A curve that looks sensible on paper can fall below what the factory will cut for a single size or colour, and then you must trade off range, colour count and quantity.
Worked Example: A Size Split for a First Order
The example below is a worked illustration, not an industry average and not advice for any particular brand. It imagines a relaxed-fit unisex hoodie in one colour for an adult audience with a moderate range, and a total of 300 pieces. The percentages come from the reasoning in the steps above: a centre at M and L, tapered ends and a small but present XS.
Illustrative size split for one worked example
Worked example, not data
- XS5%
- S20%
- M30%
- L28%
- XL17%
Illustrative only: a worked example for a hypothetical relaxed-fit adult hoodie, not an industry average. Your own audience and fit may produce a very different curve.
Applying those shares to 300 pieces gives the quantities in the table. All five lines add up to exactly 300, so no rounding adjustment was needed in this example.
The worked example in pieces (300 pieces, one colour)
| Size | Share of order | Pieces | Reasoning in the example |
|---|---|---|---|
| XS | 5 | 15 | Small group of customers, kept in range so the size is available |
| S | 20 | 60 | A meaningful shoulder of the curve |
| M | 30 | 90 | One of the two centre sizes |
| L | 28 | 84 | The second centre size for a relaxed fit |
| XL | 17 | 51 | Wide enough to serve the top end of the range |
Illustrative arithmetic: 15 + 60 + 90 + 84 + 51 = 300. Percentages are of the example order only.
Size Ratio Methods: Which to Use and When
There is more than one way to arrive at a split. The best method is the one that fits the evidence you hold, and many brands combine two. Use the table to match the method to your situation, and be honest about how much evidence each one really gives.
Size ratio methods and when to use them
| Method | How it works | Best used when |
|---|---|---|
| Bell curve from first principles | Centre on the sizes your audience wears most, taper the ends | You are new and have no sales data |
| Pre-order or waiting list data | Allocate in line with the sizes people have actually asked for | You have collected sizes before ordering |
| Sell-through from a smaller run | Use what sold fastest in a first batch or a test order | You have already sold at least one run |
| Fixed pack ratio | Order in repeating packs such as one of each size per pack | Wholesale accounts that want a standard pack |
| Customer headcount | Order exactly the sizes named by a team, club or business | Uniform or event orders with known wearers |
A general guide. Combine methods where you can, and always prefer real demand evidence over assumptions.
A bell curve is a reasonable first guess, but it should give way to real data as soon as you have any. If you want to limit the risk further, the model described in our guide to test and scale clothing manufacturing starts with a smaller test order per style before committing to depth, although it reduces risk and does not remove it.
How Size Ratios Interact With Factory Minimums
A factory does not just divide your total order by your percentages. Minimums can apply per style, per colour and sometimes per size, because each change of size or colour means cutting, bundling and line changes. Ask early how the factory counts its minimums, and whether they apply to the whole order or to each colour.
The problem for small brands is that splitting a modest total across several colours and five sizes produces very small runs at the ends. The chart shows the same example hoodie, now in the smallest of three colours at 60 pieces, with the same size shares applied.
Same size split in a small colour: 60 pieces
Pieces per size, illustrative
Illustrative arithmetic: 5, 20, 30, 28 and 17 per cent of 60 give 3, 12, 18, 16.8 and 10.2, rounded to 3 + 12 + 18 + 17 + 10 = 60. A worked example, not a factory rule.
Three pieces in one size is the sort of number a factory may question. Options include fewer colours, a shorter size range, combining the smallest sizes or accepting a higher unit cost for the awkward lines. Our guide to how bulk clothing suppliers work explains how factories think about these trade-offs.
Solid Packs vs Assorted Packs and Packing Choices
Packing affects your size ratios because it decides how the pieces are shipped and sold. A solid pack holds one size in one carton, which makes it easy to restock a single size. An assorted pack holds a set ratio of sizes in each carton, which is simple for wholesale buyers who want a standard bundle but less flexible if one size sells faster than the others.
Solid-size cartons vs assorted-size packs
Solid cartons
- Solid cartons let you restock or sell a single size easily
- Solid cartons give a clearer count at inspection and receiving
- Easier to rebalance stock between channels
Assorted packs
- Assorted packs suit wholesale accounts that want a fixed bundle
- Assorted packs speed up simple wholesale picking
- Assorted packs lock in the ratio and make rebalancing harder
A general comparison. Choose the pack type that matches how you will sell and store the stock.
If you are unsure, solid cartons give you more flexibility for a direct-to-consumer brand, while assorted packs may suit a retailer that expects them. Agree packing instructions with the factory before cutting, in the same way you agree the size split.
Size Ratios for Different Garment Types and Made-to-Order Alternatives
Garment type changes how much customers move around the curve. Relaxed hoodies and oversized t shirts let customers choose between two sizes, while fitted denim and tailored shirts make the size more exact. That is why you should not copy a split from one category into another without thinking about the fit.
If a big fixed split worries you, it is worth looking at alternatives that reduce size risk. Some brands blend a smaller stocked run of core sizes with made-to-order clothing manufacturing for the rest. Others compare blank, custom or manufactured hoodies to see which route gives enough control over sizing and cost.
How to Adjust Size Ratios on Reorder Using Real Sell-Through
Your second order should look different from your first, because by then you have evidence. Compare how fast each size sold, not only how many you sold in total. A size that sold out in days is a signal, but so is a size that never moved.
- Look at the order of selling out, not only the final count of each size.
- Check returns and exchange reasons, because a size that sells and returns is not a success.
- Separate stock-outs from low demand: a size that was unavailable cannot show demand.
- Allow for channel differences, since your website and your wholesale accounts may buy different sizes.
Not all evidence is equally reliable when you plan the next split. The ratings compare common sources by how much they tell you about true demand by size.
How reliable each source is for planning sizes
1 dot = low, 5 dots = high
| Reflects real demand | Available early | Hard to misread | |
|---|---|---|---|
| Sell-through by size from a live run | ●●●●● | ●●●●● | ●●●●● |
| Pre-orders with sizes chosen | ●●●●● | ●●●●● | ●●●●● |
| Waiting list or survey answers | ●●●●● | ●●●●● | ●●●●● |
| Competitor or online example splits | ●●●●● | ●●●●● | ●●●●● |
Indicative ratings of how well each source tends to predict real demand, not measured results.
Reorder timing matters too, because production and shipping take time and imports add customs steps. Check the current rules on the GOV.UK guidance on importing goods pages before you plan a reorder window, and ask the factory for a realistic schedule in writing.
Checklist: What to Tell the Factory About Your Size Split
A clear order sheet prevents most size mistakes. The checklist below covers the information a factory needs to cut and pack your split correctly the first time.
What to tell the factory
- Style name and number, with the size range being produced
- Quantity per size and per colour, in a simple table
- Which size is the base size for the approved sample
- The size chart and the grading rules the order follows
- Packing method: solid cartons, assorted packs or another instruction
- Labelling per size, including size labels and care labels
- Whether partial shipments or a later top-up of one size are allowed
- Who confirms the final split before cutting is released
A general list. Add anything your retailer or channel requires.
Most brands discover their real curve after launch. Where the factory allows it, ask whether a top-up run of one size is possible, and do not spread every piece across every size from day one.
Common Size Ratio Mistakes in a First Order
The most common error is an even split, with the same number of pieces in every size, because it feels fair. Real customers do not distribute evenly, so an even split leaves you short in the middle and long at the ends. The second is copying a competitor or an online example without knowing their fit or audience.
Other mistakes are ordering too many colours for the total quantity, ignoring factory minimums until the quote arrives, and skipping the record of assumptions so there is nothing to learn from. Before you send your purchase order, ask yourself one question: what would I do differently if the middle size sold out in a week?
How Ruhrose Approaches Size Ratios and First Orders
Ruhrose develops hoodies, fleece, jersey, denim and woven casualwear with production in Bangladesh and UK buyer support. We talk through your audience and size range before bulk, build samples in your base size and confirm how quantities will be cut per style, colour and size. We do not publish a standard curve, because the right split depends on your customer. Standards bodies such as ISO publish size designation standards if you want a formal reference. You can read more about Ruhrose clothing manufacturing services on the homepage.