Q&A for How to Measure an Arm Hole

Take the measurement from under the armpit to the elbow. The middle will be the thickest part of the arm, and according to the size that part comes out to, you can adjust the circumference of the sleeve.

Yes you should. Otherwise you get a piece of flabby materiel under your arm.

You can measure your arm to find your arm hole measurements. Raise your arm and hold it parallel to the floor. Either arm is fine, though it will be easiest to do your measuring with your dominant arm and use your non-dominant arm for reference. Place the “0” mark against the bony part of your shoulder joint, right where your arm meets your torso. This will serve as the starting point for your measurement. Use the pad of your thumb or forefinger to pin the end of the tape in place. Draw the tape down the front of your shoulder and under your armpit and wrap it all the way around to the original starting point. That's your measurement!

There are a few things you can do to estimate the arm hole measurement. First, spread the shirt out face-up on a flat, stable surface. Smooth out the fabric around the arm and shoulder area and do your best to eliminate all wrinkling, folding, or bunching. Take a measuring tape and position the starting end of the tape measure at the top of the seam, where it intersects with the seam originating at the garment’s neckline. Then, adjust the loose end of the tape so that it lies along the curve of the seam all the way to the armpit area. Make sure the tape is on the body of the shirt and not on the sleeve, which can mess up the accuracy of your measurements. Once you’ve got the measuring tape situated properly, look at the number aligned with the bottom of the seam and jot it down on a scrap sheet of paper. Then, flip the shirt over and measure the rear arm hole seam. Add the two measurements together to get your full arm hole measurement.

Sleeve length refers to the measurement of a shirt's sleeve. It's different than just your arm length because dress shirt sleeves are actually measured from the nape of your neck to your shoulder and from your shoulder to your wrist. That ensures that the cuffs aren't too short or too long and your shoulders fit neatly in your shirt. That's also why you need 2 separate measurements to find your proper sleeve length: your neck to shoulder and your shoulder to wrist. Having the right measurements can help you choose a shirt that fits you perfectly.