How to Build a Clothing Size Chart That Fits

Two shirts, both labelled medium, both from careful brands, and one fits and one doesn’t. The customer concludes sizing is arbitrary. It isn’t — the two brands published different things and called them the same word.

Getting a size chart right is mostly about publishing two numbers instead of one.

Body measurements versus garment measurements

A body measurement is the wearer’s chest, waist, hip. A garment measurement is the finished item, laid flat and measured.

The difference between them is ease — the room designed into the garment.

garment measurement = body measurement + ease

A 96 cm chest with 8 cm of ease gives a 104 cm finished garment. Publish only the body measurement and a customer measuring their favourite shirt gets a confusing answer. Publish only the garment measurement and a customer measuring themselves gets a different confusing answer.

Publishing both, clearly labelled, with the ease stated, is what actually reduces returns. Customers use both methods and a chart that supports one leaves half of them guessing.

Ease is why identical sizes fit differently

A fitted shirt might carry 5 cm of ease. A relaxed overshirt might carry 20 cm. Both can be labelled medium and both can be correct for their intended fit.

Which means a size label carries almost no information on its own. The ease — or a plain statement of intended fit, “close-fitting” or “relaxed” — is the part that tells a customer what to expect. It’s also, usefully, the part that lets someone decide to size up deliberately.

Grading

Grading is stepping the base size up and down by a consistent increment. Four to six centimetres of chest measurement between adult sizes is typical.

Smaller steps mean more sizes, more inventory, and better fit for more people. Larger steps mean fewer SKUs and more customers falling between sizes. It’s a commercial decision as much as a technical one, and it should be a decision rather than an accident.

Note that grading isn’t uniform across every measurement — chest, waist and hip usually step at different rates, and sleeve and body length step more slowly than circumference.

Common mistakes to avoid

• Publishing one set of measurements without saying which kind they are.
• Copying a competitor’s chart without checking it matches your actual patterns.
• Grading every measurement by the same increment.
• Omitting instructions on how to measure, which is where a large share of customer error comes from.
• Changing the base size or grading between production runs without updating the chart.

How to do it with Clothing Measurement Chart Builder

The Clothing Measurement Chart Builder generates a graded chart with ease stated explicitly.

1. Measure the base size accurately and record whether the figures are body or finished-garment measurements.
2. Choose a grading step — 5 cm between adult sizes is common.
3. State the ease alongside, so customers can tell fitted from relaxed.
4. Include short instructions on where to measure.

ISO’s sizing standards cover body measurement definitions if you need a formal reference. Other planning tools are in the tools directory.

Frequently asked questions

Should I publish body or garment measurements?

Both, clearly labelled. Customers measure themselves and also measure garments they already own, and a chart supporting only one method causes returns.

What is ease?

The difference between the body and the finished garment. Close-fitting shirts carry a few centimetres, relaxed outerwear far more. It’s the biggest reason two garments of the same size fit differently.

How much should sizes step?

Four to six centimetres for adult clothing. Smaller steps mean more inventory; larger steps mean more people fall between sizes.

Final thought

State the ease. It’s one number, it explains the whole mystery of inconsistent sizing, and almost nobody publishes it.

Try the free Clothing Measurement Chart Builder