Measure your chest at the fullest part, keeping the tape level and snug but not tight
Measure your shoulders from one shoulder point to the other across the back
Measure your sleeve length from the shoulder seam to the wrist bone
Measure your jacket length from the base of the neck to the desired hem point
Measure your waist at the narrowest part of your torso
Compare your measurements to the brand’s size chart
Use chest measurement as the primary suit jacket size reference
Check whether the jacket is labeled in short, regular, or long lengths
Try the jacket on and confirm the shoulders sit flat without pulling
Confirm the sleeves show about a quarter to half an inch of shirt cuff
Confirm the jacket closes comfortably without strain at the buttons