Neckline Adjuster
Raise, lower, widen, or narrow any neckline. Get the adjusted CF/CB lengths and updated facing depth — for both front and back.
Neckline Depth
Neckline Width
Shift the shoulder end of the neckline — creates a wider boat neck or narrower scoop.
Depth vs. width
A neckline has two dimensions: depth (how far it plunges at center front or center back) and width (how far it extends toward the shoulders). These can be adjusted independently.
Lowering the depth moves the center front or center back neckline point downward — the curve gets longer and the garment's CF/CB length increases by the same amount. Widening moves the shoulder end of the neckline outward — the shoulder seam gets shorter on the neckline side.
The facing rule
Every neckline adjustment must be transferred to the facing, lining, or binding. The facing is cut from the same neckline curve, so when you redraw the neckline, the facing inner edge must follow. If you lower the neckline by 1" and don't adjust the facing, the facing won't reach the new neckline edge and the garment won't finish properly.
Enter your current facing depth above and the calculator will give you the updated dimension.
Trueing the curve
After adjusting, fold the front and back pieces along the shoulder seam with necklines aligned. The front and back neckline curves should meet smoothly at the shoulder. If there's a jog or angle at the join, blend it out with a French curve before cutting.
This is the same trueing step used for any shoulder seam adjustment — any time you change the neckline shape, check the shoulder join.