How do I measure my neck?

Measure around the base of your neck where a necklace would sit. The tape should be snug but comfortable. A typical women’s base-of-neck measurement is 34–38cm. This is the body measurement, not the finished garment opening.

How long should neckline binding be?

For a knit neckband, cut the strip to about 85% of the neckline opening — the stretch lets it sit flat when applied. Ribbing stretches more, so cut to about 75%. For woven bias binding there is no stretch, so cut to 100% of the neckline plus about 2cm for the overlap/join.

What determines the neckline drop?

The neckline drop is how far below the base of the neck the neckline sits at centre front. A standard round/crew neckline drops about 7–8cm. A scoop neck drops 10–12cm. A deep V can drop 12–20cm or more. The back of the neck stays a shallow ~2cm scoop on most styles.

Why must the opening clear my head?

A pull-on neckline with no opening fastening must stretch over the head. The accepted minimum finished opening is about (head circumference + neck circumference) ÷ 2 for a knit with roughly 50% stretch. This calculator floors the result at that minimum so the garment can actually go on.

SewCalcs

Neckline Calculator — Neckline Dimensions & Binding

Calculate neckline opening dimensions and binding strip length for various neckline styles.

Neck Circumference

Base-of-neck body measurement (where a necklace sits), e.g. 34–38cm

Neckline Drop

Depth of the front below the neck base

Neckline StyleNeckline shape (round, V, scoop, boat, square)

Binding TypeHow the binding is cut — sets the strip length

How We Calculate This

The neckline opening is built from its real cut geometry, not by shrinking your body neck measurement. The opening width across the shoulders is set by the style (boat widest, V and crew narrowest), and the front contour is measured along the actual cut line.

The method

V-neck front = 2 × √((width÷2)² + drop²) — the two diagonals (Pythagoras).

Round / scoop / boat front = half-ellipse arc of half-width × drop.

Square front = width + 2 × drop (two sides + base).

The back is a shallow ~2cm scoop. The total opening is floored at (head + neck) ÷ 2 so it always clears the head.

Binding length = opening × 0.85 (knit), × 0.75 (ribbing), or × 1.00 + 2cm (woven bias).

Frequently Asked Questions

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Last updated: June 2026

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