Armscye Calculator — Armhole Circumference

The armscye (also called armhole) is the opening in a garment where the sleeve attaches. It is the curved seam line around the shoulder and underarm. The armscye circumference determines how the sleeve fits into the bodice.

Measure around the armhole seam line on the garment (or pattern). Include front and back armhole lengths. Alternatively, estimate from body measurements: bicep circumference plus ease plus 8cm works for a basic set-in sleeve.

Sleeve cap ease is the extra length in the sleeve cap seam line over the armhole seam line, which is distributed evenly so the sleeve sits smoothly over the rounded shoulder. For woven set-in sleeves it is roughly 6-10% of the armhole circumference (around 2.5-4.5cm on an average armhole). This calculator works it out as a percentage of the armhole circumference, which you can adjust under Advanced Options.

A common drafting guideline for women is armhole depth = bust circumference ÷ 6 + 1.5 inch (3.8cm), which gives about 19cm for a 90cm (36 inch) bust. Raise the armhole (less depth) for a fitted, active garment. Lower it for comfort and ease of movement.