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Button Size Chart: Ligne to mm and Inches (14L to 60L)

Complete ligne to millimetre and inch conversion for garment buttons, 14L to 60L, with the size used for shirts, polos, trousers, jackets, coats and denim. One ligne equals 0.635 mm, or one fortieth of an inch.

Reference tableUpdated 2026-11-06

One ligne (L) equals 0.635 mm, or one fortieth of an inch. A 24L button is 15.2 mm across, which is the standard front button on a men's shirt. Ligne measures the outside diameter of the button only — not the shank, not the height. The table below is the conversion we quote from, and the range we hold dies for.

Ligne to millimetres: full conversion table

Ligne to millimetres: full conversion table
LigneMillimetresInchesTypical use
14L8.9 mm0.350 inBabywear, doll clothes, shirt collar and cuff
16L10.2 mm0.400 inChildrenswear, blouse front, shirt cuff
18L11.4 mm0.450 inShirt front placket, blouse, polo placket
20L12.7 mm0.500 inStandard shirt front, polo, light jacket
22L14.0 mm0.550 inTrouser waistband, casual shirt, overshirt
24L15.2 mm0.600 inMen's shirt front, chinos, polo
27L17.2 mm0.675 inBlazer front, jacket, light coat
28L17.8 mm0.700 inBlazer front, tailored jacket
30L19.1 mm0.750 inCoat, denim jacket, workwear
32L20.3 mm0.800 inCoat, heavy shirt, denim tack button
34L21.6 mm0.850 inHeavy coat, duffle, denim waistband
36L22.9 mm0.900 inHeavy overcoat, outerwear
40L25.4 mm1.000 inOvercoat, decorative front, leather
44L27.9 mm1.100 inCoat, statement front, bag hardware
48L30.5 mm1.200 inDecorative, upholstery-weight fabric
54L34.3 mm1.350 inDecorative, costume, heavy outerwear
60L38.1 mm1.500 inDecorative, oversized styling

Which size for which garment

Which size for which garment
GarmentCommon ligneMillimetres
Babywear and infant14L-16L8.9-10.2 mm
Childrenswear, 2-8 years16L-18L10.2-11.4 mm
Men's dress shirt18L-20L11.4-12.7 mm
Polo and casual shirt20L-24L12.7-15.2 mm
Trouser waistband22L-24L14.0-15.2 mm
Blazer and tailored jacket27L-28L17.2-17.8 mm
Coat and workwear30L-32L19.1-20.3 mm
Denim tack button27L-32L17.2-20.3 mm
Heavy overcoat and duffle34L-36L21.6-22.9 mm

These are the ranges the trade works to, not a rule. A designer can put a 30L on a shirt as a styling decision — the constraint that matters is the buttonhole, and the buttonhole is set on the counter sample.

How to measure a button you already have

Use a digital or vernier caliper across the widest point of the face. Do not measure the shank, the rim height or the thread hole — ligne is the outside diameter of the face only. For a domed button, the widest point is at the base of the dome.

Measure ten pieces from the lot and report the range, not a single number. A 24L button that measures 15.0 mm to 15.5 mm is within normal production tolerance; that spread is what you should write into the specification, because a flat "24L" is not enforceable at the inspection table.

Three things buyers get wrong

Reading L as a length. Ligne is a diameter. A 36L button is 22.9 mm across — it is not 36 mm, and it is not longer than a 24L button. Quotes that treat L as a linear measure are usually coming from a trader who does not make buttons.

Assuming the ligne scale is universal at the factory floor. Some Asian factories quote in whole millimetres (15 mm instead of 24L, 18 mm instead of 28L). Both are correct; they are different notation for the same button. When you compare two quotations, convert to millimetres first, or you will compare two different sizes and think you found a price difference.

Leaving the tolerance off the spec. Write the size as 24L (15.2 mm ± 0.3 mm) in the trim specification and on the trim card. Without a tolerance band, a lot measuring 15.6 mm is technically not your 24L — and on a close-fitting placket that half millimetre is a button that will not pass through the hole.

Button size and buttonhole

The hole is cut from the button diameter plus the fabric thickness, so a 24L button on a 0.6 mm shirting does not need the same buttonhole as the same button on a 3 mm wool coating. This is why we cut the buttonhole position on the counter sample rather than on a drawing. If the fabric changes after the sample, the buttonhole should be re-checked, even when the button does not change.

FAQ

Send the button size, the fabric weight and the care label and we will cut the buttonhole position on a counter sample for your approval before a die is cut.

Senfa Mfg Email: [email protected]

Last updated: 2026-11-06

What size is a 24L button in mm?
24L is 15.2 mm, or 0.600 inch. It is the standard front button on a men's shirt and on chinos.
Is 18L or 20L right for a men's shirt?
18L (11.4 mm) is common on slim and formal shirts; 20L (12.7 mm) is the mainstream menswear size. Both are stocked. The choice is a styling decision, and it should be fixed before the placket is graded.
What size button goes on a coat?
30L to 32L (19.1 mm to 20.3 mm) for a single-breasted coat, 34L to 36L (21.6 mm to 22.9 mm) for a heavy overcoat or duffle. The bigger sizes carry more torque at the shank, so attachment strength matters as much as the diameter.
Why is my "24L" button not exactly 15.2 mm?
Moulding tolerance. Resin and urea shrink slightly on cooling, so a nominal 24L commonly measures 15.0 mm to 15.5 mm. This is normal and should be covered by a tolerance band in the specification rather than treated as a defect.
Do shell buttons follow the same ligne scale?
Yes. Shell is graded by the same ligne scale, but the natural thickness of the shell limits how large a thin-walled button can be made, so 40L and above in shell are cut from thicker blanks and cost more per gross.
Can you supply a size that is not on this chart?
Sizes outside 14L to 60L need a new cutting die — and, for metal or injection-moulded resin, a new mould. Send the millimetre target and the fabric weight, and we will confirm what is achievable and what the die or mould lead time is before you commit to the specification.
Download the size chart (PDF, A4)Printable A4 version of both tables — tape it inside the sample-room cabinet.