A size chart looks simple: a row of sizes along the top, some measurements down the side. But two charts that look identical can mean completely different things, and misreading one is the most common reason an online order does not fit.
Body measurements or garment measurements?
This is the single most important thing to work out.
- Body measurements tell you the size of the person each size is made for. A chart that says size M is "chest 96 to 101 cm" means it is designed for someone whose chest measures 96 to 101 cm.
- Garment measurements tell you the size of the clothing itself, laid flat. A chart that says size M is "chest 54 cm" usually means the garment measures 54 cm across from armpit to armpit, so 108 cm all the way round.
A garment is always bigger than the body it is made for, otherwise you could not move in it. That extra room is called ease. So if you compare your 98 cm chest with a garment measurement of 108 cm, the shirt is not "10 cm too big". It has 10 cm of ease, which is typical for a regular fit t-shirt.
How to tell which kind you are looking at:
- Words like "body", "to fit" or "your measurements" mean body measurements.
- Words like "garment", "flat", "product measurements" or "across" mean garment measurements.
- A chest figure around half of what you would expect is almost certainly a flat garment measurement. Double it.
Centimetres or inches?
Most brands publish one or the other, and some show both. One inch is 2.54 centimetres. On clothly's size chart pages every chart is shown in both, so you never need to convert by hand.
Ranges and single numbers
Body charts often give a range for each size, such as 96 to 101 cm. If you fall inside the range, that size is made for you. If you are at the top of one range and the bottom of the next, you are between sizes. Garment charts usually give a single number, because the garment has one fixed size.
Which measurement matters?
Not every row matters equally for every garment.
- T-shirts, shirts and knitwear: chest first, then length and shoulder.
- Jackets and coats: chest and shoulder, with room for what you will wear underneath.
- Trousers and jeans: waist and inseam, then hip for slimmer cuts.
- Dresses: chest, waist and hip together, since the dress has to fit all three.
If one measurement puts you in a small and another in a medium, go with the one that matters most for that garment.
Letter sizes and number sizes
Letter sizes, from XS to XXL, are not standard between brands. One brand's medium can be another's small. Numeric sizes vary too: jeans sized by waist in inches are often cut larger than the number suggests, and European, UK and US numeric sizes all use different scales. The chart is the only reliable guide; the label on the size is just a name.
Fit notes
Many charts come with a note such as slim, regular or relaxed fit. That tells you how much ease the brand has added. The same chest measurement in a slim fit will sit much closer to the body than in a relaxed one.
A quick checklist
- Work out whether the chart shows body or garment measurements.
- Check the unit.
- Find the measurement that matters most for this garment.
- Find your number in that row, and read the size at the top.
- If you are between sizes, choose based on how you like the fit.
Or skip the checklist: screenshot the listing and clothly reads the chart, works out which kind it is and compares it with your own measurements for you.