How to Calculate Button Size

Calculating Button Sizes

Button Size

Button sizes are recognized worldwide with “L” or “ligne” which is a French term to measure length. A ligne measurement starts at 1 and is abbreviated to 1L. ligne is a linear unit (1/40 inch) used to measure diameter of buttons. The L is measured in 0.025 millimeters or 0.635 inches. The L is measured across the diameter of the button using the widest portion.

Button sizes can vary from 10L (6.35mm to 0.25mm) up to 60L (38.1mm to 1500mm) or larger.

How to measure the button

The most common way to measure buttons is with vernier caliper. The vernier caliper is a tool used to measure round and cylindrical objects. Its adjustable jaws hold your button in place and can get an exact measurement.

• If you’re using a round button :- the measurement is the diameter of the button.
• If you’re using shaped button (oblong or an oval):- the measurement will be the longest edge or diameter.

Most vernier calipers use metric and imperial measurements. Not ligne, unfortunately. So if you’re working in ligne, you’ll need to convert your sizes.

With the help of below method you can calculate button size easily Before calculating button line we should know following details:

• 1 inches = 40 ligne = 2.54 cm,
• 1 ligne = 0.635 mm

So If the Button measurement is 15 mm (vernier caliper or tape reading)

• 1 ligne = 0.635 mm
• Button die (in mm) / 0.635 = button ligne
• 15 mm / 0.635 = 23.62 = 24 L

So if required you could calculate button diameter from button ligne also. 

• Button diameter = Button Ligne X 0.635
• 23.62 (24) X 0.635= 15 mm

Button Size Matrix

Line	Inches	Millimeters
10-line	0.250	6.35mm
14-line	0.362	9.2mm
16-line	0.413	10.5mm
18-line	0.457	11.6mm
20-line	0.500	12.7mm
21-line	0.531	13.5mm
22-line	0.559	14.2mm
23-line	0.583	14.8mm
24-line	0.590	15.0mm
27-line	0.661	16.8mm
28-line	0.701	17.8mm
30-line	0.748	19.0mm
32-line	0.807	20.5mm
34-line	0.846	21.5mm
36-line	0.902	22.9mm
40-line	1.000	25.4mm
60-line	1.500	38.1mm
80-line	2.000	50.8mm
100-line	2.500	63.5mm
120-line	3.000	76.2mm