For a man who wears a suit, the fit of the jacket is a vital element of the image he projects. If the jacket is too tight, people may see him as awkward and ineffective. If it's too loose, he may look lazy and unkempt. A proper fitting suit jacket, however, projects an individual who is confident, well-groomed and thoughtful.
Room to Move
When trying on jackets, raise and lower your arms to ensure that the jacket does not pull at the shoulders; make sure that the jacket falls to its previous position without you having to pull at the fabric. The armhole should be big enough to move your arms freely. However, just as you should not sacrifice comfort for style, do not do the reverse, either. When you move your arms and shoulders, allow a slight snugness.
Check Out All Angles
Check out the suit jacket from all angles. Make sure it can be buttoned without the bottom front straining or the side or back vents gaping open. On the other hand, watch out for a boxy look or a too-roomy feel in the chest, shoulder blades or rear. The fabric of the jacket should fall smoothly and the jacket should be slightly tailored for a crisp, professional look.
Adjust to Body Type
The classic American suit hangs fairly straight on the body. A man with a slim, athletic build may prefer to check out British and European styles of jackets which are known for tapered waists and may be a little snug in the rear with no vents to gape. This is a more precise fit than a looser-fitting jacket that could require alterations to get just the right fit. A man with a large girth may need an executive-style suit, designed for more room in the waistline.
While the traditional suit jacket is made of wool or a wool blend, not all jackets are meant to be formal or businesslike. A young man may enjoy wearing a casual, form-fitting longer jacket made of a lightweight fabric or blend. The jacket can be worn as part of a suit or with jeans and perhaps a trendy or retro hat. Such a jacket may be worn open, with or without a tie.