Measuring tailored suit jackets and sport coats can be tricky, but taking the following precautions will produce the best results:
1. Button the jacket up fully.
2. Lay the garment on a flat, hard surface to ensure accuracy.
Lay the jacket face down. Use your hands to smooth and flatten out the body of the jacket. Measure from where the shoulder seam meets the sleeve on one side of the jacket straight across to where the shoulder seam and sleeve meet on the other side.
Lay the jacket on its back. It’s important that the jacket is buttoned up fully. Use your hands to extend and flatten out the chest and torso completely. The bottom front hem (quarters) of the jacket should fall below the back hem of the jacket, such that the jacket can lay as flat as possible along the sides. Pop the collar up such that the lapels lay over each other as flatly as possible. Position the sleeves pointing up so that you can find the absolute corner where the side of the jacket meets the armpits. Measure from this point straight across the suit jacket to the opposite edge where the armpit and torso meet.
With the jacket laying on its back and fully buttoned, again use your hands to extend and flatten out the torso completely. Measure straight across from one edge of the jacket waist to the other edge. On a two button jacket, position the measuring tape straight along the top button. On a 3 button jacket, the measuring tape should pass right through the middle button.
With the jacket laying on its back and fully buttoned, again use your hands to extend and flatten out the body of the jacket completely. Measure straight across from one edge of the jacket’s hips to the other edge. On a two button jacket, position the measuring tape horizontal across the body, starting 6″ below the top button. On a 3 button jacket, the measuring tape should cross the body horizontally, 6″ below the middle button.
Center Back Length
Lay the jacket face down. Pop the collar such that the melton (felt) is visible beneath the collar. Starting from the intersection of the back, collar and center back seam, measure down along the center back seam to the bottom hem of the jacket.
Lay the jacket face up. Use your hands to smooth and flatten the sleeve down alongside the body. Measure from the beginning of the sleeve where it meets the top shoulder seam, following the curve of the padding at the head of the sleeve before rotating straight down to the end of the cuff.
Sleeve Bicep Width
Lay the jacket flat on its back. Pull the sleeve straight out to the side. The measurement should be 1” from the armpit up to the top of the sleeve, in a line that is perpendicular to the top of the sleeve.
Sleeve Opening Width
Lay the jacket on its back and use your hands to smooth out the sleeve. With the cuff fully buttoned, spread it flat and measure across from side to side.