Collar size

Collar size is the length of a dress shirt's collar, from the center of the button to the far end of the buttonhole. Shoppers find theirs by measuring the neck at its base with one finger under the tape, the room a buttoned collar needs. Shirts sold by collar size usually step in half inches: 15, 15½, 16.

How to measure

1. Stand straight, chin level, shoulders relaxed.
2. Wrap the tape around the base of the neck, where a collar sits, just below the Adam's apple.
3. Slip one finger under the tape and read. Between two marks, take the larger.
4. Or lay a shirt that fits flat, collar open, and measure from the center of the button to the far end of the buttonhole.

The template step: "around the base of your neck, one finger under the tape."

On a size chart

The Men's shirts template lists the neck in centimeters, two per size; the inches are the centimeters divided by 2.54:

Its fit note: "Choose your collar size first, then check the chest." A chart should say whether it lists the shopper's neck or the collar itself.

In Ruban Size

Find my size asks for the neck and the chest, and the one that needs the larger size wins: a 41 cm neck with a 100 cm chest reads "You are between M and L. We suggest L." When a chart lists the collar itself, set "Measurements in the table" to garment measurements in its Fit tab, and it adds 1, 1.5 or 2.5 cm to the shopper's neck for Snug, Regular and Loose. Try it on the Men's shirts template.