Why has my size changed without me changing?

Womenswear sizing has drifted larger for decades, so the same body maps to a smaller number over time. The measurements are what stayed constant.

What should I tell a retailer?

Your chest and waist in centimetres. Those mean the same thing everywhere, and the size label does not.

Conversionsapparel

Clothing Size Converter

Clothing sizes from body measurements. Menswear is usually sized on the chest measurement itself, which is why it converts cleanly; womenswear uses arbitrary numbers that have drifted downwards for decades.

Also called: uk to us clothing size, international size chart.

Letter size

S on a chest of 96 cm. That is UK 38, US 38, EU 86 and Italian 82. Menswear is sized on the chest measurement itself, so the number means something physical.

Italy

Chest in inches

37.8

Waist in inches

32.3

On sizing drift

Menswear is sized on the chest measurement itself, so the number means something physical.

How this is calculated

Method and background

How this is calculated

Menswear sizing is largely honest: a 38 jacket means a 38 inch chest, so it converts by arithmetic. Womenswear numbers correspond to nothing physical and have drifted: a garment labelled size 8 today is several inches larger than one labelled 8 in the 1960s. That drift, sometimes called vanity sizing, means a conversion table is a rough guide and the measurement in centimetres is the reliable number to give a retailer.

the offsets are conventions that brands apply loosely, and menswear is usually sized on the chest measurement directly

s: Size

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

a 96 cm chest in menswear

Chest or bust: 96
Waist: 82
For: Menswear

Letter sizeS

96/2.54 rounds to 38

Open this example

womenswear uses a different scale

Chest or bust: 91
Waist: 74
For: Womenswear

Letter sizeM

boundary: US runs four below UK

Open this example

Method and limits

What it assumes

Standard body measurements taken over light clothing.

What it deliberately does not model

Brand variation in womenswear routinely exceeds two sizes.
Fit style, whether slim, regular or relaxed, changes the right size independently of measurement.

Formula version 1.0.0 · definition 1.0.0 · India · Report a problem with this calculator

Frequently asked questions

Why has my size changed without me changing?: Womenswear sizing has drifted larger for decades, so the same body maps to a smaller number over time. The measurements are what stayed constant.
What should I tell a retailer?: Your chest and waist in centimetres. Those mean the same thing everywhere, and the size label does not.