Everyday Life⏱ 4 min read
How to Calculate Your Clothing Size from Body Measurements
Clothing sizes vary wildly between brands and countries. Here is how to take accurate measurements, use them to find your size in UK, EU, and US systems, and calculate alterations.
A single clothing size number tells you almost nothing reliable — a size 12 in one brand may fit like a size 10 in another. Body measurements are the only consistent reference point.
Key Measurements to Take
Measure over underwear (not clothing), standing straight.
Use a flexible measuring tape, level and snug but not tight.
Bust/Chest: fullest part of the chest, tape horizontal
Waist: narrowest point, usually 1 inch above the navel
Hips: fullest part of the hips/seat, approximately 8-9 inches below waist
Inseam: from crotch to ankle (for trousers)
Inside leg: same as inseam — crotch to floor while standing
UK Women's Size Chart
UK SizeBust (cm)Waist (cm)Hips (cm)
882-8463-6588-90
1086-8867-6992-94
1290-9271-7396-98
1494-9675-77100-102
1698-10279-83104-108
18104-10885-89110-114
Size Conversions Between Systems
Women's dress sizes:
UK 8 = EU 36 = US 4 = AUS 8 = FR 36
UK 10 = EU 38 = US 6 = AUS 10 = FR 38
UK 12 = EU 40 = US 8 = AUS 12 = FR 40
UK 14 = EU 42 = US 10 = AUS 14 = FR 42
UK 16 = EU 44 = US 12 = AUS 16 = FR 44
Men's shirt collar sizes:
UK/US: 14.5, 15, 15.5, 16, 16.5, 17 (inches)
EU: 37, 38, 39, 41, 42, 43 (cm collar circumference)
To convert: UK collar (inches) x 2.54 = EU collar (cm)
Calculating Alterations
Common alteration: taking in or letting out a seam
Trouser waist too large by 4cm:
Seam at each side: 4cm / 2 = 2cm to take in per side
(Trousers have 2 side seams, so split equally)
Hemming trousers:
Current inside leg: 82cm
Desired inside leg: 76cm
Amount to take up: 6cm
Add 2-3cm hem allowance if rehemming: cut to 79cm, turn up 3cm
Dress taken in at waist:
4cm total reduction across 4 seams (2 side, 2 centre back/front):
= 1cm per seam to take in