What a size chart is and how to read it

What you take from this lesson: Understand where a garment's sizes come from and why two different brands don't fit the same.

The chart doesn't describe anyone

A size chart is a list of average bodies. Each row is a size and each column is a measurement. The important thing to understand is that these bodies don't exist: they are a statistical average chosen so that a garment works for as many people as possible.

Nobody measures exactly what the chart says. And yet clothes produced from that chart fit many people well, because ease absorbs the difference.

Why an M is not the same at every brand

Because each brand uses its own chart. There is no international standard requiring a size M to mean a particular bust circumference. Each company picks the chart that describes its customer.

A young streetwear brand and a classic clothing brand can use the same size name and differ by ten centimeters in circumference. Neither one is wrong: they are aimed at different customers.

For anyone producing clothes, the practical conclusion is simple: define your own chart once and then stick to it across all your styles. A customer who bought an M and liked the fit should be able to buy another M without trying it on.

How to read it

The columns are the body measurements (bust, waist, hip) and the rows are the sizes. The jumps between sizes are not the same for every measurement or across every part of the range: between the middle sizes they are usually 4 cm of circumference, and at the extremes they sometimes get larger.

The chart describes the BODY, not the garment. The garment is always larger than the body, and that difference is ease, which is decided style by style.

Which chart the catalog patterns use

Moldey patterns are graded on a standard production size chart, the one the industry commonly uses. That means a pattern you buy will fit close to what the market expects.

If a brand already has its own chart and needs all its garments to fit exactly alike, the way to go is custom pattern development: the pattern is drafted on that chart instead of the standard one.

In short

A size chart is a list of average bodies, one per size. There is no universal standard: each brand picks its own, and what matters is sticking to it across all your styles.