Your jacket should fasten snug but not tight against your waist. You should be able to move around comfortably but without gaps between your body and the jacket - almost like the jacket is giving you a light hug.

The jacket sits away from your body or there is significant visible pulling when the jacket top button is fastened.

Your jacket sleeves should rest just above your wrist when your arms are relaxed at your sides, showing off around half an inch of your sleeve cuff underneath. NOTE - this length is shorter than 90% of off-the-rack jackets, which are made to fit long arms. When you raise your arm up to shake someone's hand, the jacket sleeve may appear shorter than you're used to. This is normal and expected.

Your shirt sleeves (if they are correctly sized) do not show below the jacket, or if more than one inch of the shirt sleeve is visible at rest.

Your jacket should fasten snug but not tight against your waist. You should be able to move around comfortably but without gaps between your body and the jacket - almost like the jacket is giving you a light hug.

The jacket sits away from your body or there is significant visible pulling when the jacket top button is fastened.

The jacket collar should sit smoothly against your shirt collar, following the natural shape of your neck without pulling, bunching, or leaving visible gaps.

The collar is pulling away from the neck or creating wrinkles across the back.

Your jacket should just about cover your full bottom, but no longer. Modern styles favor a slightly shorter finish, but the jacket should still always cover at least 3/4 of your backside.

A significant portion of your rear is visible or if the jacket hangs below the base of your butt.