The armhole is the opening where the sleeve is set into the body of a jacket. It is the detail a client sees least and feels most: the armhole decides whether raising your arm drags the whole jacket up with it, whether the shoulder sits clean, and whether your suit moves with you or against you.
What is the armhole in a jacket's construction?
The armhole is where the jacket's three most important panels meet: the front, the back, and the sleeve. The cutter must settle two measurements here:
- The armhole circumference: how large the opening is relative to your actual arm.
- The depth of the armpit point: cut high, close to the hollow of your underarm, or dropped lower down the body.
It sounds counterintuitive, but the classic rule of tailoring is this: a high, trim armhole is more comfortable than a wide, low one. When the bottom of the armhole sits close to your underarm, the sleeve moves independently of the body — you reach for something and the jacket's hem and shoulders barely stir. A dropped armhole, typical of mass-produced ready-to-wear, hoists the entire jacket every time you move.
Why does the armhole matter so much?
- It cannot be fixed after the jacket is made. Shoulders, waist, and hems can all be altered; a badly cut armhole essentially means rebuilding the coat. This is why careful tailors measure and fit the armhole more attentively than anything else.
- It decides how clean the shoulder and chest look. A correct armhole lets the chest cloth lie flat, without collapsing into creases when your arms hang.
- It is the dividing line between bespoke and ready-to-wear. Factory jackets must drop the armhole to fit many bodies; a tailored jacket cuts it to one man's underarm — which is where that "weightless" feeling first-time bespoke clients are so surprised by comes from.
How to test the armhole at a fitting
- Button the jacket and raise both arms straight up: if the hem lifts more than 3–4 cm and does not settle back when you lower your arms, the armhole is too low.
- Shake hands, reach forward, mimic holding a steering wheel: tension across the back or upper arm signals the armhole or sleeve width is short of what you need.
- Stand side-on to a mirror and study the cloth around the armhole: a correct one shows only soft, moving folds — never a fixed diagonal crease.
- Note: a properly high armhole never digs into the underarm — if it pinches, the circumference is short, not the armhole too high.
Common mistakes about the armhole
- Assuming a wide, low armhole means comfort — the opposite is true, and it is the main reason jackets ride up in motion.
- Slimming the waist and shoulders while ignoring the armhole, producing a jacket that looks trim standing still but pulls out of shape in motion.
- Judging a jacket from photos of a static pose; the armhole only reveals its quality when the wearer moves.
- Asking a tailor to "cut the armhole higher" on a finished jacket — cloth already cut away cannot be restored, so this alteration is very limited.
A word from Mon Amie's artisans
At Mon Amie, the armhole is a measurement we take directly at the client's underarm rather than deriving it from chest size, because two men with the same chest can differ by a full two centimeters here. At the basted fitting, our artisan will ask you to raise your arms, shake hands, and sit down — precisely to read how the armhole behaves before the finished sleeve is set. If a suit has ever felt restrictive under the arms, do not rush to blame the size; in most cases the armhole was cut low and cut wrong, not the jacket too small.
Book an appointment to have your armhole measured to your own frame, and learn more about the tailoring process at Mon Amie.