How to Measure a Suit Jacket or Blazer - Online Buying Guide

In our latest Video Details Series, Leah demonstrates how to measure one of your own jackets for purchasing a new jacket online.

Buying a jacket online that fits beautifully is actually a surprisingly simple process if you take a few comparison measurements off one of your own jackets. We have measurement tables below to select the correct sizing in both cm and inches.

In the video, Leah discusses the below four key measurement points:

  • Shoulder Width (know as Point to Point)
  • Shoulder Seam
  • Length of Jacket
  • Jacket Sleeve




There are two main things to keep in mind. The most important measurement is the shoulder width (known as the point to point measurement), shown first in the video. The reason for this is as long as the jacket fits across the shoulders, almost all other aspects can be adjusted by your local alterations tailor who tend to be very affordable. 

The other rule of thumb is, if you are in doubt between two sizes, always go for the larger size as a jacket can be taken in, e.g. waist, length, sleeves etc, but can't generally be taken out.


To begin, take a measuring tape and choose one of your own jackets fits you well. In the video we have demonstrated on a mannequin, but you can just as easily do this on a table.  

1. Shoulder Width
Known as the point to point measurement, measure across the back of the shoulders from the seam of the sleeve head to the opposite seam. This is an important measurement as some people typically wear the same size but have different shoulder widths.

 2. Shoulder Seam
Lift up the collar, then measure from underside of the collar where the fabric meets the collar along the shoulder seam, straight down to the seam of the sleeve head.

shoulder seam

3. Jacket Length
Start by lifting the collar, then place the tape measure where fabric meets the collar at the seam in the centre of the jacket then measure all the way down to the bottom hem of the jacket. 

4. Jacket Sleeve
This is usually easier if you place the jacket on a hanger first. Take the tape and place it just above the sleeve head to take account of any shoulder padding, then measure down the centre of the sleeve to the end of the cuff.


Now you have the key measurements you can compare to our sizing charts below in either cm or inches, so you can be confident our jacket will fit you well. 

We have included the chest and waist measurements for those that are aware of their measurements, but please note these are taken on your body not a jacket. However, from our perspective the key measurements are the shoulder width, length and sleeve length, with the shoulder seam being an additional reference point. 

navy jacket red tie

The tables below sets out the different fit sizes in centimetres in the familiar UK/US and EU sizes.