Button Spacing Calculator
Calculate even button placement for shirts, coats, and dresses.
Enter placket length and count to get exact position of each button from top to bottom.
Button spacing on garments ensures an even, professional distribution of buttons along a placket, waistband, or bodice. Uneven spacing looks amateurish and can cause fabric to gap or pucker.
The core formula:
Spacing Between Buttons = (Total Placket Length − (Button Diameter × Number of Buttons)) / (Number of Buttons − 1)
Simplified version when button size is ignored:
Spacing = Available Length / (Number of Buttons − 1)
What each variable means:
- Total Placket Length — the usable length of the button band from the top button position to the bottom button position
- Button Diameter — the physical size of each button (subtract this to avoid buttons overlapping)
- Number of Buttons — total buttons including both end positions
Worked example: A shirt placket runs 55 cm from collar to hem. You want 7 buttons, each 1.5 cm in diameter.
Usable length = 55 − (7 × 1.5) = 55 − 10.5 = 44.5 cm Spacing = 44.5 / (7 − 1) = 44.5 / 6 = 7.42 cm between buttons
Practical rules:
- Women’s blouses: typically 6–8 cm spacing
- Men’s dress shirts: 8–10 cm spacing
- Children’s garments: 4–6 cm spacing (larger gaps risk choking hazards — use snaps instead for under 3s)
- Waistbands: 1–2 buttons only, no spacing calculation needed
Tips: Mark button positions from the center outward so any rounding error distributes evenly at both ends. For curved plackets, measure along the curve, not straight across.