Men's shirt sizes: a real source of frustration

Size 39 or size 41? When it comes to finding the right men's shirt size, you're often faced with a jungle of sizing systems. Every country has its own standards - and that's not all: even within a single brand, sizes can vary. Standard sizes don't suit everyone, because they're based on statistical averages that don't always reflect the full range of builds. A size M at one brand can easily be an L at another. Frustrating, isn't it?

On top of these variations, ready-to-wear sizes are often designed first and foremost around manufacturing constraints. The result is an approximate fit that doesn't always live up to expectations. Fortunately, there's a way around this — and that's exactly what LE CHEMISEUR® solves.

Where men's shirt sizes come from: FR, US, UK

Sizing systems differ from one country to the next, shaped by manufacturing needs and regional body types. The standards were developed in different eras, often for specific historical reasons.

France: French sizes are given in even numbers - 38, 40 or 42. They're based on the neck measurement, in centimetres. This system comes from haute couture, which shaped ready-to-wear after the Second World War.

United States and United Kingdom: in the US and UK, sizes are given in inches and combine neck size with sleeve length (for example, 16"/34"). The system was originally created for military needs in the 19th century. Some brands also use more general sizes - Small, Medium, Large - which only adds to the confusion.

These differences come down to different manufacturing traditions and body types from one region to the next. For today's customer, it makes choosing the right men's shirt size more complicated than it should be.

Size conversion guide: FR, US, UK

The sizes we use correspond to the shirt's collar measurement, in centimetres. The collar size is usually shown inside your off-the-shelf shirts; below, you'll find how it converts to US and UK sizes:

Your size - calculated, not guessed

Our technology takes the guesswork out of standard sizes. You give your weight, height and age, and answer two quick questions. Our algorithm does the rest: the exact measurements for a men's shirt that fits you perfectly.

How it works

• Simple and precise - No complicated measuring. A few details are enough: the algorithm works out your ideal cut from the measurements of 50,000 customers.
• Made for every build - Broad shoulders, slim chest, fuller waist? The system adapts. The result: a shirt that fits right, comfortable and sharp.
• The Fit Key - reorder in one click - A 5-character code that keeps all your measurements. Your next shirts? Same perfect fit, no starting over.