Move the shoulder point inwards by slashing and overlapping, so the armhole sits where your arm actually joins the body — the armhole circumference stays the same.
Recognise it first. The shoulder seam extends past the shoulder point and drops down the arm, and a diagonal drag line runs from the shoulder point towards the bust or the shoulder blade. Choosing a smaller size instead makes the body too tight to solve a shoulder problem, which is why fitting the shoulders and adjusting elsewhere is the usual advice.
The method. On the front piece, mark a point roughly a third of the way down the armhole from the shoulder. Draw a line from there to the shoulder seam, perpendicular to it, and a second short line from the same point across to the armhole edge. Cut along both lines, leaving a hinge at the armhole edge. Overlap the shoulder end by the amount to be removed — usually 5 to 15 mm per shoulder — and tape.
Redraw the armhole as a smooth curve through the step the overlap has created.
Do the same on the back piece, by the same amount, or the shoulder seams will not match.
Then walk the shoulder seams front to back, and walk the armhole against the sleeve cap. The armhole length should be almost unchanged; if it has shrunk noticeably, reduce the sleeve cap ease to match.
Test it on a toile. Shoulder adjustments are small numbers with large visual effects, and 10 mm is usually enough.
Questions people actually ask
Do I need to change the sleeve?
Usually not, because the armhole length barely changes. Walk the cap against the new armhole and adjust the ease only if it has moved noticeably.
What about broad shoulders?
The same method in reverse: spread the cut apart instead of overlapping, and redraw the armhole through the gap.
Last reviewed 2026-08-11