How to take garment measurements (and turn them into a Size Chart)

Most fashion brands measure their clothes flat on a table. Shoppers measure their own body. When a product page only shows the first, shoppers have to guess what it means for them. Some guess right. Many order two sizes, send one back, or don't order at all.

This guide covers how to take garment measurements properly for tops, jackets, dresses and trousers, and how to turn them into a Size Chart your shoppers can actually use.

Garment measurements vs body measurements

Before you pick up a tape measure, it helps to know which of the two you are making.

  • Garment measurements describe the item itself. For example, a shirt that is 52 cm across the chest when laid flat.
  • Body measurements describe the person the item is made for. For example, a chest of 94 cm measured around the body.

The two are never the same number. A garment is always bigger than the body it fits, because people need room to breathe, move and wear things underneath. That difference is called ease, or room to move.

Shoppers know their body measurements, or can take them in a minute. So the most useful Size Chart shows body measurements to pick a size from, and garment measurements so shoppers understand the fit.

What you need

  • A soft measuring tape in cm or inches
  • A flat, clean surface such as a large table
  • One sample of each size, ideally from the production run, not a prototype
  • A sheet or notebook to write everything down per size

Lay each garment flat and smooth it out without stretching it. Close zips and buttons. Measure every size the same way, in the same place, so your numbers are comparable.

How to measure tops, shirts and hoodies

  • Chest: measure straight across from one side seam to the other, about 2.5 cm (1 inch) below the armholes. This is often called pit to pit.
  • Length: from the highest point of the shoulder, next to the collar, straight down to the hem.
  • Sleeve: from the shoulder seam to the end of the cuff. If your style has no shoulder seam, measure from the centre back of the neck and say so in your chart.
  • Waist (fitted styles only): straight across at the narrowest point.

How to measure jackets and coats

Measure jackets the same way as tops, with the zip or buttons closed. Two things to watch:

  • Jackets are worn over other layers, so they need more room to move than a shirt. Keep that in mind when you turn your numbers into body sizes.
  • If the sleeves or waist can be adjusted, measure them fully open.

How to measure dresses

  • Bust: straight across, just below the armholes.
  • Waist: straight across at the narrowest point, or along the waist seam if there is one.
  • Hip: straight across at the widest point, usually about 20 cm (8 inches) below the waist.
  • Length: from the highest point of the shoulder down to the hem.

How to measure trousers and jeans

  • Waist: button the waistband and measure straight across the top edge.
  • Hip: straight across at the widest point, usually just below the bottom of the fly.
  • Inseam: from the crotch seam down the inside of the leg to the hem.
  • Rise: from the crotch seam up to the top of the waistband at the front.
  • Leg opening: straight across the hem, if your styles vary in width.

Flat or all the way around?

Both are fine, as long as you say which one you used. Flat measurements are faster and more common. Measurements all the way around are easier for shoppers to compare with their own body.

The conversion is simple. For anything that goes around the body, like chest, waist and hip, a flat measurement times two gives the full measurement. A chest of 52 cm flat is 104 cm around. Length, sleeve, inseam and rise stay the same, because they don't go around the body.

This is the most common mistake on product pages: flat measurements shown without saying they are flat. A shopper with a 96 cm chest sees 52 cm, and has no idea what to do with it.

How to turn garment measurements into body sizes

To tell a shopper which size to pick, you need the body measurement each size is made for. Here's how to get there:

  1. Get the full measurement. Double your flat chest, waist and hip measurements.
  2. Take off the room to move. The amount depends on the fit you designed.
  3. Turn the results into ranges. Each size covers the bodies from just above the size below it, up to its own number.

These are common starting points for chest room to move. They are not rules, and every brand cuts a little differently:

Garment and fit Room to move at the chest
Slim shirt or T-shirt about 4 to 6 cm (1.5 to 2.5 in)
Regular shirt or T-shirt about 8 to 12 cm (3 to 5 in)
Relaxed or oversized top about 14 to 20 cm (5.5 to 8 in)
Jacket or coat worn over layers about 10 to 20 cm (4 to 8 in)

Stretch fabrics need less room to move, and fitted jeans often have almost none at the waist.

An example. A regular fit T-shirt measures 54 cm across the chest in size M.

  • 54 cm × 2 = 108 cm around the shirt
  • 108 cm minus 10 cm of room to move = 98 cm
  • If size S works out at 92 cm, size M fits a chest from 93 to 98 cm

That's the number a shopper can compare with their own chest.

Check it on real people

Room to move is an estimate until you've tested it. Before you publish, try two or three sizes on people whose measurements you know. If someone with a 96 cm chest feels M is tight, your room to move is too small. Adjust it and every size moves with it.

Your customer reviews and return reasons help too. Comments like "runs small" or "size up" on one product usually mean its room to move is lower than the rest of your range.

What a good Size Chart shows

  • Body measurements to pick a size from, in cm and inches
  • Garment measurements, labelled clearly as flat or all the way around
  • A short note on the fit, for example "relaxed fit, size down for a closer fit"
  • A small drawing of where each measurement is taken
  • The same layout across all products, so shoppers learn to read it once

Make it quicker with the free Size Chart generator

You don't have to do the maths by hand. Our free Size Chart generator takes your garment measurements, flat or all the way around, applies the room to move for your fit, and gives you a Size Chart with body sizes in cm and inches. You can copy the table or download it as a CSV.

If you'd rather show every shopper their size directly, AI Frame puts your Size Chart on your Shopify product pages and recommends each shopper's size next to the size picker. Shoppers can also see the product on their own photo with Virtual Try-On.

Quick answers

Should I show garment or body measurements?

Both. Body measurements help shoppers pick a size. Garment measurements help them understand the fit.

Why are my flat measurements so much smaller than my customers' measurements?

Because they only cover the front of the garment. Double them to get the full measurement around.

Do I need to measure every product?

Measure every style with a different cut. Products that share a pattern, like the same T-shirt in five colours, can share one Size Chart.

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