Suit Size Calculator

This is the jacket size only — a suit also has a length (short, regular, long) and a trouser waist, and neither follows from the chest. The European number is always ten more than the US one, so a EU 50 is a US 40; it is not a measurement in centimetres.

A jacket is bought by a single number, and that number is not your chest measurement — it is the nearest size step to it. This page performs that conversion, a short chain of unit changes with one rounding in the middle, and gives the answer in both its European and its American form. Take the preset 102 cm. Divided by 2.54 that is 40.16 inches; halved it is 20.08, which rounds to 20; doubled again it is US 40, and the European number is that plus ten, so EU 50. The halving and the doubling are what force the result onto even steps, and that is where the tolerance sits: anything from 100 to 104 cm lands on EU 50, while 99 cm has already dropped to 48. One measurement buys one part of the answer. Chest circumference carries neither the jacket length nor the trouser waist, so both are absent here on purpose — the first follows from your height, the second from a measurement this page never asks for. The real limit is what a size step is. It places you inside a band of roughly five centimetres of chest, which is enough to pick a jacket off the rail but not enough to say how that particular jacket will sit across the shoulders or the back. Anything finer than the step comes from the fitting room, not from arithmetic.