Industrial size chart: how it is built and used

What you will learn

Understand what an industrial size chart is, what information it holds and how it is used to grade a pattern.

Before you start

It helps to have seen the previous lesson ("What is industrial patternmaking").

Concept

An industrial size chart is a spreadsheet with the reference body measurements for each size in a size range (for example S, M, L, XL), and with the increment between one size and the next for each key measurement (bust, waist, hip, length, etc.).

Lesson content

What information it holds

• Reference measurements per size (bust circumference, waist, hip, sleeve length, etc.)
• Increment between consecutive sizes (e.g.: +4 cm of bust circumference per size)
• Sometimes, pattern-specific measurements (not just body measurements), which already include design ease

What it is used for

The size chart is the reference used to grade (scale) the base pattern: instead of recalculating each size by hand by measuring the body again, the chart's increments are applied at each point of the pattern. It is what makes the 6 sizes of the same garment keep the same shape and proportion.

Step by step

1. Pick a garment and a size range (e.g.: S to XL).
2. Find or build a simple chart with the bust circumference of each size.
3. Calculate how much the bust circumference increases between each pair of consecutive sizes.

Practical example

If size M has a 96 cm bust circumference and size L has 100 cm, the increment between M and L is 4 cm for that measurement.

Common mistakes

Using the same size chart for any type of garment: A t-shirt size chart doesn't work the same for pants: each type of garment is graded differently depending on which measurements are critical to its fit.

Modeltex tip

If you are going to produce with a workshop or a factory, ALWAYS ask for the size chart they will use before approving the sample: it avoids surprises when the full graded lot arrives.

Exercise

Take an industrial size chart (you can ask the Modeltex Lab AI for an example) and calculate the waist circumference increment between 2 consecutive sizes.

Frequently asked questions

Do all brands use the same size chart?

No. Each brand or manufacturer can define its own chart based on its audience. That is why one brand's size M may not be the same as another brand's M.

Does the size chart replace the base pattern?

No: the chart gives the reference measurements per size, but the base pattern is still needed to define the real shape of the garment. The chart is used to grade it.

Summary

The industrial size chart defines the reference measurements and the increments between sizes in a size range, and it is the basis for grading (scaling) a pattern consistently across the whole production run.

Go back to the full course or ask the Modeltex Lab AI.