It's easy to lose track of all the different trouser sizes and forget your own. Fortunately, the LE CHEMISEUR® styling team, specialists in made-to-measure shirts and trousers, are here to explain it all!

Let's start with jeans. Since jeans come straight from the U.S.A., they keep the American sizing system everywhere in the world. You've certainly already seen a jeans label reading W32 x L34!

If that rings a bell, that's normal. In the United States, W32 stands for "Waist 32", meaning a 32 waist measurement, and L34 stands for "Length 34", meaning a 34 leg (or inseam) length. It's not only jeans brands that use this system – many more formal trouser brands have also adopted this American sizing system. The problem is that there isn't really a standard, and not every brand follows it. What's more, to make things trickier, there can be a slight discrepancy in trouser size correspondence from one brand to another. Maybe you wear a 43 at Nike and a 44 at Adidas? It's exactly the same with trouser manufacturers.

How to find your way around and finally know your trouser size

The first option is to rely on our French/American trouser size conversion charts and follow our tips to determine your trouser size as precisely as possible!

If you own a pair of jeans, you can find your French size using our chart matching American sizes to French sizes. For example, if you're wondering which French size corresponds to a 32 34 jean, you can work out that you should look for a French size 42.

Men's trousers: French to American size conversion chart

In theory it's simple:
The French size is half the waist measurement, expressed in cm, and the US size is the waist measurement, expressed in inches. Since 1 inch = 2.54 cm, French size = US size x 2.54/2.

*the difference is explained by vanity sizing in trouser sizes

French to American trouser size correspondence: accounting for vanity sizing

While there is indeed a theoretical equivalence between French and American trouser sizes, in reality the observed correspondence between French and American sizes is slightly different, with American sizes tending to run larger than French sizes. Many American brands practice "vanity sizing", a practice that consists of "over-sizing" products to flatter the consumer and make them believe they can still fit into the same trouser size they wore at 20.

Inseam length correspondence chart between French and American sizes

Discover in this chart which inseam length corresponds to French sizes (given in centimeters) and which inseam length corresponds to American sizes (given in inches - IN).

Find your trouser size based on your weight

Don't know your trouser size? The second option is for anyone who's really tired of racking their brain over sizing questions. Thanks to its AI-powered algorithm that predicts your measurements, LE CHEMISEUR® calculates your perfect fit in a few clicks, using your weight, height and age.

Know your trouser size at the waist

You can measure your waist directly.

Take the measurement where you usually wear your belt, pulling it in slightly, using a tape measure. Careful – what you find isn't your French size! Use the chart above to find your French size or its US equivalent.

Measuring inseam length on the body is trickier. We recommend simply checking the label of a pair of trousers you own that fits well and hasn't been altered! Or measuring the inseam length of trousers that fit you, following the inseam seam down to the hem.