What is an armhole

Sep 12, 2026

Short answer: The armhole is the opening where the sleeve is attached to the body of a top. Its size decides how freely you can move your arm without the whole top moving with it when you reach up or forward.

Where the armhole sits

The armhole is the opening in the body of a top that the sleeve is sewn into. It runs from the shoulder seam, down under the arm and back up the other side. You cannot see it as a hole once the top is finished, but you can feel it. Its height and width decide how the top behaves when you move.

High or low armhole

A high armhole sits close up in the armpit and gives the most freedom of movement. It sounds backwards, but when the opening sits high, the arm can move on its own without pulling on the body of the top. You can reach up, forward and sideways, and the top stays in place. See socks for men.

A low armhole feels looser

A low armhole gives a relaxed look with more room under the arm. Many find it comfortable when sitting still or out for a walk. But the top lifts when you reach up, because the arm takes fabric from the body with it. You see it most at the hem, which rides up over the waist. See bamboo hoodie for men.

Where you notice it most

In workwear and training clothes, the armhole matters more than any other measurement. When you lift, stretch or move your arms all day, this is where the top either moves with you or gets in the way. For a calm day at the office or on the sofa it matters less, and a lower armhole is fine. See bamboo sweatshirt for men.

How to test it

Put the top on and reach both arms straight up over your head. Look in the mirror to see how far the hem lifts. Then reach your arms forward as if holding a steering wheel. If it pulls across the back or the top rides up over your stomach, the armhole sits low or tight. If it stays put, it suits movement.

Armhole and size

A larger size does not always give a better armhole. Often the armhole gets both wider and lower as the size goes up, and then the top lifts even more when you reach. If the top fits across the shoulders and chest, it is better to keep the size and look for a style with a higher armhole instead.

The fabric plays a part

A soft fabric with stretch gives a little extra room in the armhole, because it gives when you move your arm. A firm fabric without stretch makes the difference between a high and low armhole more obvious. That is why two tops with almost the same cut can feel different. Test it while moving, not just standing still.

A choice, not a quality difference

Neither a high nor a low armhole is better in itself. The high one suits movement and work, the low one a relaxed look and quiet days. Think about what the top is for before you choose. Many keep both in the wardrobe: a closer fitting top for active days and a looser one for home.