Dress-shirt fronts
A standard 4-hole front button is 11-15 mm across, roughly 18L-24L. Buttons sit 75-90 mm apart on the placket, and most shirts carry 2 spares in the side seam.
Sizing a Replacement Button
Measure the old button across its widest point, or measure the buttonhole and subtract 3 mm. A standard dress-shirt front button is 11-15 mm across; coat and blazer buttons run 25-40 mm. Sizes are sold in lignes — 1 ligne equals 0.635 mm — so one quick conversion tells you exactly what to ask for.
01
Diameter across the widest point is the only number sizing needs. If the button is gone, measure the buttonhole and subtract 3 mm — a 15 mm hole was cut for a 12 mm button.
02
Convert millimetres to lignes by dividing by 0.635, then check the garment band: 16L-18L for cuffs, 24L-32L for cardigans, 36L-60L for coats. Shirt fronts sit at 11-15 mm, coats at 25-40 mm.
03
Choose sew-through for shirting, a shank button or thread shank for thick cloth, and a tack button for denim. Cut any new buttonhole 3 mm longer than the diameter, and lock the thread with 3-5 winds and a knot.
Each garment family has a settled size band, so naming the garment narrows the size before you measure anything.
Size bands map to garments in the trade: 16L-18L (10-11 mm) covers cuffs and children's wear, 24L-32L (15-20 mm) covers cardigans, and 36L-60L (23-38 mm) covers coats. A standard 4-hole dress-shirt front button is 11-15 mm across, which sits between the cuff and cardigan bands.
Coat and blazer buttons run 25-40 mm in diameter. That range overlaps the top of the coat band, so a blazer replacement usually lands around 40L-48L (about 25-30 mm), while a heavy overcoat can take up to 60L (38.1 mm).
Jeans and workwear jackets break the pattern: they use tack (nail) buttons with a cap of about 17-20 mm, clinched through the cloth rather than sewn.
A standard 4-hole front button is 11-15 mm across, roughly 18L-24L. Buttons sit 75-90 mm apart on the placket, and most shirts carry 2 spares in the side seam.
The smallest band, 16L-18L or 10-11 mm. Cuffs take 1-2 buttons each.
The middle band, 24L-32L or 15-20 mm. On thick knits, sew flat buttons with a thread shank of fabric thickness plus 1-2 mm.
The top band, 36L-60L or 23-38 mm; coat and blazer buttons run 25-40 mm in practice. Shank buttons, stocked 8-20 mm, keep the overlap flat over thick cloth.
Tack (nail) buttons replace sewing entirely: a cap of about 17-20 mm is clinched through the cloth onto a stud.
Wind the thread around the shank 3-5 times, push the needle through to the back and knot. This lock is what keeps a replacement button on.
Cut a buttonhole 3 mm longer than the button diameter: a 12 mm button needs a 15 mm buttonhole.
A flat sew-on button needs a thread shank equal to the fabric thickness plus 1-2 mm, so the overlap lies flat.
| Ligne size | Millimetres | Inches | Typical use |
|---|---|---|---|
| 16L | 10.2 mm | 0.40 in | Cuffs, children's wear |
| 18L | 11.4 mm | 0.45 in | Cuffs, light shirt buttons |
| 24L | 15.2 mm | 0.60 in | Cardigans, dresses |
| 28L | 17.8 mm | 0.70 in | Cardigans |
| 32L | 20.3 mm | 0.80 in | Cardigans, light jackets |
| 36L | 22.9 mm | 0.90 in | Coats |
| 44L | 27.9 mm | 1.10 in | Coats and blazers |
| 60L | 38.1 mm | 1.50 in | Overcoats |
The figures cited are trade-standard conventions for button sizing and attachment, restated in the sections above.