About this tool
This calculator works out your suit jacket size from a chest measurement and your height, entirely in your browser with nothing uploaded. Measure your chest around the fullest part, under the arms and across the shoulder blades, keeping the tape level, and enter your height in the same unit.
Jacket sizes are numbered by chest measurement in inches, rounded to the nearest even number — so a 40-inch chest is a size 40. A length letter is added from your height: S (short) under 5'8", R (regular) from 5'8" to 6'1", and L (long) above 6'1" — giving a size like 40R. The EU size is the number plus 10 (a 40 becomes a 50), the UK uses the same number-and-letter as the US, and the recommended chest range shows the measurements that round to this size. Build (slim, regular or athletic) is shown as the fit style to look for on the rack.
Jackets are cut with built-in ease, so choose the size from your body measurement rather than adding room yourself. If you are between two even numbers, most people prefer the smaller for a trimmer chest and the larger for extra shoulder room.