What is my blazer size

When shopping for menswear you usually know your shirt and pant size. When it comes to blazers and suits though, people are far more uncertain about what their correct size is. Part of this is a function of not shopping for blazers very frequently. A decent blazer can last you a lifetime and even if you wear them every day you are much more likely to be buying dress shirts or pants on a regular basis than suit jackets. There are times though when you do find yourself shopping for a new blazer. Maybe you outgrew your old jacket, maybe it’s summer and you need something lighter or you want to jazz up your wardrobe with something more colorful such as pink or light blue linen jacket. Wearing wool in the scorching heat of summer is quite an ordeal. You want something that rises the formality of a coat and tie without the insulation of heavy fabric. You need a cloth that can breathe.

The best way to know if a blazer will fit is to try it on. That being said, there are a variety of situations where this is not possible such as ordering online, getting something made to measure or looking to have an existing garment adjusted. Regardless, even if shopping in person for ready-to-wear items it’s helpful to be able to narrow your search based on your size as well as having an additional heuristic for knowing if something fits. Suits are expensive so the last thing you want to do is spend a fortune on something that you later find out isn’t quite your size. A starting point is to take measuring tape and measure the fullest part of your chest. This is found at your thorax at the perimeter running under your arm pits. This ought to correspond to your blazer size. Many sizing guides will stop here as far as providing you with instruction to identify your size. Clothing is about more than just size though, it’s about fit. You want something comfortable the suits your style and body type. How tall you are, how slender you are, how comfortably you want to be able to button the front buttons on the jacket all play a role in determining the optimal size.

Let’s walk through a few examples of blazers comparing the chest size to the blazer size. Starting with an example chest size of 40 inches let’s compare how that maps to a few different blazers. First off, a checkered saffron and green blazer which unfortunately doesn’t specify the size in the label but which fits comfortably, is a little too wide but the sleeves are a little too short. When putting the blazer on, the circumference comes out to 40. If we try on a 42R slim fit i.e. 42 chest size, regular sleeve length and slim fit we find that we can comfortably button both front buttons. The jacket is not at all baggy which leads us to conclude that 40R slim fit would have been too tight. The sleeves are a tad too long but it’s not apparent that a different chest size would change that. Moving on to a navy plaid jacket labelled 44S the fit is very comfortable albeit a little loose however it is within an acceptable standard deviation where it would come down to personal preference rather than being the wrong size. If you like a looser fit this is entirely appropriate. It should also be noted when buying a blazer that if you want to able to enjoy it for a very long time and are between two sizes it is better to order the larger size. This is a relaxed fit as suppose to a slim fit. Something frustrating about trying to figure out a blazer’s size particularly when looking at vintage clothing is that the unlike a button-down shirt where the label is prominently placed right under the midpoint of the collar, with jackets the size is not consistently listed in the same location if at all. Make sure to look in the inside pockets when trying to locate the size tag. Suits also have a higher likelihood of being bespoke or adjusted by a tailor onsite which is why you are less likely to have a sizing tag included. A source of vexation nevertheless. Trying on a 39R black wool blazer. It fits. Both buttons can be buttoned although when the second button is buttoned it can feel tight. It’s definitely wearable and looks fine, just that the waistline is a little on the tighter side and could easily be an inch wider. Compared to a blue cotton blazer listed as 40R/W34 this feels a little top heavy. The shoulders and top part of the jacket are fine. However, it seems to narrow at the level where you would button the buttons and runs a tad tight. It makes for an asymmetrical look since it’s tighter around the waste while having spare room at the shoulders. As a result, it gives a baggy aesthetic at the shoulders even thought they are the correct size since the button stance pulls the jacket in at the waistline. Essentially, the jacket is not uniform in terms of how much fabric is used with more fabric used at the top. Unlike shirts, buttons do not run down the entire middle of a suit. There are two or three buttons at the waistline level. If the jacket waistline is too narrow and you button it, this accentuates the difference between waist size and chest size. The act of tightening the suit by passing the button through the button hole pulls the jacket in unnaturally creating a triangular look where the lapel is pushed out leading to a gap between the lapel and the dress shirt rather than sitting nicely on your chest. Ideally you want both the chest and waist measurements to be appropriate so that when you button the top button as is expected, the jacket closes with the lapel still sitting comfortably on your chest rather than bending outwards and creasing.

There are three main conclusions from running these experiments. When trying to determine your blazer size from your chest size you need to add two inches to what you measure in order to get your size. Adding four inches gets you to a looser fit depending on your preference. If you are ordering an entire suit pay attention to the pant size as well and make sure to order your correct waistline. The biggest takeaway though is that given the expense and infrequency with which one purchases blazers as well as the variation in sizing and fit you are well advised to actually try it on in person to make sure it works for you.