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.

How do I measure armhole circumference?

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.

What is sleeve cap ease?

Sleeve cap ease is the difference between the sleeve cap circumference and the armhole circumference. Typically 2-4cm for woven fabrics. This extra fullness allows the sleeve to fit smoothly over the shoulder curve.

How do I adjust the armhole depth?

A general guideline for armhole depth is bust circumference divided by 6, plus 2-3cm. Raise the armhole (less depth) for a fitted, active garment. Lower it for comfort and ease of movement.

SewCalcs

Armscye Calculator — Armhole Circumference

Calculate armscye (armhole) circumference and adjustments.

Bust Circumference

Bust measurement

Bicep Circumference

Enter the bicep circumference

Shoulder Width

Across one shoulder

Ease

3-5cm for standard fit

How We Calculate This

Armhole circumference is estimated from the bicep measurement plus ease. Armhole depth is derived from bust circumference. Sleeve cap height is a proportion of armhole depth.

The formula

Armhole circ ≈ Bicep + Ease + 8cm

Armhole depth ≈ Bust circ ÷ 6 + 2.5cm

Sleeve cap height ≈ Armhole depth × 0.6

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.