Stained Glass Lead Came Length Calculator
Calculate the total length of lead came or copper foil needed for a stained glass panel based on piece count and size.
Calculating lead came for stained glass panels
Lead came (pronounced “kaim”) is the H-shaped channel that holds glass pieces together in traditional stained glass. Copper foil (the Tiffany method) is an alternative where thin copper tape wraps each piece’s edge. Both methods require estimating the total linear length of material.
Lead came estimation formula:
Interior came = (Number of pieces × Average perimeter per piece × 0.5)
The 0.5 factor accounts for shared edges — each interior edge is shared between two pieces, so you only need came for half the total edge length.
Border came = Panel perimeter
Total came = Interior came + Border came + 10–15% waste
Average piece perimeters by panel complexity:
| Panel Style | Pieces per m² | Avg Piece Perimeter | Description |
|---|---|---|---|
| Simple geometric | 15–25 | 35–50 cm | Large rectangles, few curves |
| Moderate | 25–40 | 25–40 cm | Mixed shapes, some curves |
| Detailed | 40–60 | 20–30 cm | Smaller pieces, intricate design |
| Highly detailed | 60–100+ | 15–25 cm | Very small pieces, complex curves |
Lead came sizes:
| Size | Heart Width | Leaf Height | Best For |
|---|---|---|---|
| 3/16" (5mm) | 5 mm | 5 mm | Fine detail, small pieces |
| 1/4" (6mm) | 6 mm | 6 mm | Standard interior lines |
| 5/16" (8mm) | 8 mm | 8 mm | Heavier interior lines, emphasis lines |
| 3/8" (10mm) | 10 mm | 10 mm | Border came, structural support |
| 1/2" (13mm) | 13 mm | 13 mm | Large panel borders, window perimeters |
Worked example — moderate panel, 60 × 90 cm, 30 pieces:
Average piece perimeter: ~32 cm
Interior came: 30 × 32 cm × 0.5 = 480 cm = 4.8 m Border came: 2 × (60 + 90) = 300 cm = 3.0 m Subtotal: 7.8 m With 15% waste: 7.8 × 1.15 = 8.97 m → round to 9 m
Lead came is sold in 6-foot (1.83 m) strips. You need: 9 ÷ 1.83 = 4.9 → buy 5 strips.
Copper foil alternative:
For the Tiffany (copper foil) method, you need tape for every edge since each piece is individually wrapped.
Copper foil = Number of pieces × Average perimeter per piece + 15% overlap waste
Using the same example: 30 × 32 cm × 1.15 = 1,104 cm = 11 m of foil tape.
Copper foil comes in rolls of 33 feet (10 m) or 100 feet (30 m). Common widths: 3/16", 7/32", 1/4" — chosen based on glass thickness (standard is 3mm or 1/8").
Zinc came for borders: Many stained glass artists use zinc came (U-channel) for the outer border instead of lead. Zinc is stiffer and provides better structural support for panels that will be installed in windows. Calculate border length the same way.