Sweater Size Ratio Planning: How Many of Each Size to Order

By YZR Sweaters · 2026-09

Every knitwear order ends with the same quiet decision: how many units of each size to produce. Buyers often answer it from memory, repeat last season's breakdown without checking whether it worked, or borrow a ratio from someone else's range. That guess is one of the most expensive habits in knitwear buying, and one of the easiest to improve with data you already have.

What is a size ratio in apparel ordering?

Size ratio (also called a size breakdown or size curve) is the number of units of each size you order within a single style: how a 1,200-piece order splits across S, M, L and XL. It is not the size chart, the table of body measurements each size is built to, and it is not grading, the rules that scale a pattern from one size to the next. The size chart and grading describe what the garment measures; the size ratio decides how many of each you buy. The three are often confused, but only the ratio is a commercial decision you own as the buyer.

Why does an even split across sizes fail?

Dividing an order evenly, the same quantity of S, M, L and XL, assumes demand is spread evenly too. It is not. Adult body sizes cluster around the middle of a range, so on most knitwear styles the middle sizes sell fastest and the sizes at the ends sell slowest, and the pattern shifts with the style, the market and the channel. An even split creates two problems at once: the sizes most customers want run out first, while the sizes at the ends stay on the shelf. If a style is new, build its ratio from comparable styles you already sell rather than defaulting to an even split.

How do you build a size ratio from your own sales data?

Sell-through — the share of the units you ordered that actually sells — is what this decision is measured by. Four steps turn ordinary sales records into a ratio you can order against.

• Check what sold by size, and what was left. A sold-out size and an unsold size tell opposite stories.
• Remove stockout distortion. When one size sells out, the other sizes absorb its demand and look stronger than they are.
• Build a ratio per category. Sweaters, cardigans and knitted dresses do not sell in the same proportions.
• Separate basics from fashion. Core styles settle into a stable ratio; fashion shapes stay provisional until they sell through.
• Order conservatively at first. On a new style, trim the outer sizes and replenish rather than betting a full season.

What else changes the right size breakdown?

Your own data is the foundation, but several factors push the ratio in different directions. Body size and fit preference vary by market, so a ratio that clears one country can leave a size unsold in another. Silhouette matters as much: a relaxed, oversized sweater is forgiving and sells across fewer sizes, while a close-fitting knit leaves no room for error. Channel matters too, because a store lets customers try the garment on while an online order is returned when the fit misses. Heavier layering sweaters tolerate sizing better than fine-gauge knits worn close to the body.

What does a wrong size ratio cost?

Two losses, in opposite directions. Broken sizes come first: the fastest-selling size runs out while the season still has weeks left, and the sale goes to whichever brand still has stock. Dead stock comes second: the slow sizes reach the end of the season unsold and can only be cleared at a discount deep enough to erase their margin, as we describe in our guide to knitwear dead stock clearance. In most ranges the markdown on leftover sizes costs more than the small risk of ordering slightly too few of a proven seller.

How do extended sizes affect the ratio?

Extending a style into larger or smaller sizes is a genuine growth opportunity, but demand at the ends of the range is harder to predict because it depends on how the fit is graded and who the style is for. Common practice is to add extended sizes to a core style in small quantities, watch the sell-through for a season or two, and only then give those sizes their own ratio. Our notes on plus-size knitwear sourcing cover how to approach the category with a supplier.

How should you share the ratio with your supplier?

Send a size breakdown table per style rather than one total quantity. Before production is booked, confirm four points: whether the minimum order quantity (MOQ, the smallest quantity a factory will produce) applies per style or per size; whether the ratio can still change before yarn is purchased; whether individual sizes can be topped up later; and how long a size-specific top-up takes. Factories that knit to order can usually follow the ratio you provide, but the flexibility has to be agreed before the schedule is fixed. Our guide to how sweater MOQ works explains how minimums are normally calculated.

Common mistakes in size ratio planning

The same errors appear again and again: copying a competitor's ratio, splitting every order evenly, reading sales numbers without allowing for stockouts, applying a basic style's ratio to a fashion style, and never recording sell-through by size, which makes improvement impossible because there is no data to work from. The final mistake is committing a whole season in one order instead of sending a first batch and replenishing the sizes that prove themselves.

A size ratio is not a fixed rule but a working hypothesis that each season's data either confirms or corrects. Two or three seasons of size-level sell-through are enough to turn ordering from a guess into an adjustment, and that adjustment is where much of the margin hides.

Frequently asked questions