Finding your size: how to measure yourself and your clothes
Find your size in centimetres with a tape measure and a garment that fits well. How to measure armpit width, back length, waist, hips and inside leg.
In short
- Lay a garment that fits you well flat, measure it and compare those centimetres with the item’s measurements.
- A width measured flat × 2 is the garment’s circumference.
- For tops, dresses and coats, armpit width and back length matter most; for trousers, it’s waist, hips and inside leg.
- A garment is always slightly roomier than your body; that extra room (the ease) varies by style.
The size label in second-hand clothing doesn’t tell the whole story. A size 38 from fifteen years ago fits differently from a 38 today, and one brand differently from another. The most reliable way to know whether something will fit: compare centimetres. All you need is a tape measure and a garment that fits you well.
Why measuring flat works
At GSYL we measure every garment flat on a table: buttoned or zipped up, without pulling the fabric. That way you measure the width of one side. The advantage is that you can do exactly the same at home with your own clothes. Then you’re comparing like with like.
The two key measurements of a top, dress or coat
- A
- Back length: from the collar seam at the back of the neck straight down to the hem.
- B
- Armpit width: from armpit to armpit, straight across the front, just below the sleeve seams.
How to measure a garment that fits you well
- 1
Choose a piece that fits well
Take a garment of the same type: a blazer for a blazer, trousers for trousers.
- 2
Lay it flat
On a table or the floor, buttoned up and smoothed out. Don’t pull the fabric.
- 3
Measure the width
Measure straight across from seam to seam: from armpit to armpit on a top, from side seam to side seam at the waist or hips on trousers or a skirt.
- 4
Measure the length
The back length from the collar seam to the hem; for trousers, the inside leg from the crotch to the hem.
- 5
Compare
Put your centimetres next to the item’s measurements. A difference of a centimetre or two is usually within the margin; with a bigger difference, it will feel noticeably looser or tighter.
Which measurements matter for each garment?
| Garment | Key measurements | Also check |
|---|---|---|
| Tops, jumpers and blouses | Armpit width, back length | Sleeve length |
| Blazers and coats | Armpit width, back length | Sleeve length; room for a jumper underneath |
| Dresses | Armpit width, waist width, back length | Hip width on a fitted style |
| Trousers | Waist width, hip width, inside leg | How high the waist sits |
| Skirts | Waist width, skirt length | Hip width on a pencil skirt |
| Shoes | EU size | Heel height; the last (shoe shape) varies by brand |
Measuring yourself: bust, waist and hips
No garment to compare with? Then measure yourself, in underwear or thin clothing, keeping the tape measure straight and not too tight.
- Bust: around the fullest part of your bust, passing under your armpits.
- Waist: around the narrowest part of your torso, usually just above your belly button.
- Hips: around the widest part of your hips and bottom.
- Inside leg: from your crotch to your ankle, along the inside of your leg.
A garment always needs to be a little roomier than your body. How much ease it needs depends on the style: a fitted blouse has little room, while an oversized jumper or a coat that has to go over a jumper needs plenty.
From body measurement to garment measurement
Armpit width measured flat × 2 is the garment’s circumference. If your bust measures 90 cm, a fitted top with an armpit width of about 46 to 48 cm will fit. For a loose jumper or a coat, it can be more.
Why second-hand sizes can fit differently
Sizes haven’t always been the same everywhere. Older clothes often come up smaller than the same size today, and sizes vary by country and by brand. That’s why centimetres are so much more reliable than the label. Still want to know which size roughly corresponds? Check the women’s size chart for converting clothing and shoe sizes.
Frequently asked questions
How do I measure the armpit width of a garment?
Lay the garment flat and buttoned up, and measure straight across from one armpit to the other, just below the sleeve seams. Multiply by two for the circumference at chest height.
What is the back length?
The length of the garment at the back: from the collar seam at the back of the neck straight down to the hem.
What does ‘measured flat’ mean?
That the garment is lying flat on a table and you measure one side, without stretching it. So a width measured flat is half the circumference.
How much roomier than my body should a garment be?
That depends on the style and how you want to wear it. So ideally, compare with a garment that fits you well: it already has the right amount of ease built in.
Know your measurements?
Filter the shop by your size and check the measurements in centimetres for every item.