Size Converter

Button Size

Buttons are usually measured in ligne (also written "L"), but patterns and customers often talk in mm or inches. Type into any field — the others update instantly.

L
The standard button-size unit, e.g. 18L, 24L, 32L
mm
Diameter measured straight across the button
in
Common in US and UK patterns
Approximate size

Use as a rough guide, not a tape measure.

Common Button Sizes

Quick reference for the sizes most often used in sewing

Size Ligne mm Inches Common on
Conversion: 1 ligne = 0.635 mm exactly (defined as 1/40 inch). That gives mm = ligne × 0.635 and inches = ligne ÷ 40.
Calibrate Screen

Hold a bank card against your screen and adjust until the line is exactly as long as the short side of the card.