Bezel Strip Length Calculator

What is a bezel setting?

A bezel is a thin strip of metal (fine silver, sterling silver, gold, or copper) that wraps around a stone and is pushed over the edges to hold it in place. It is the oldest and most secure stone-setting method, dating back thousands of years.

Bezel strip length formula:

For any stone, you need to measure the circumference (perimeter) and add material for the solder joint.

Round stones:

Strip length = π × diameter + (2 × metal thickness)

The extra 2 × thickness accounts for the overlap at the solder joint — each end of the strip adds one thickness of metal to the outside measurement.

Oval stones:

Strip length = π × ((length + width) / 2) × (1 + (3h²)/(10 + √(4 - 3h²))) + (2 × thickness)

Where h = (length - width) / (length + width). This is Ramanujan’s approximation for an ellipse perimeter, accurate to within 0.01%.

A simpler approximation: Strip length ≈ π × √((length² + width²) / 2) + (2 × thickness)

Square and rectangular stones:

Strip length = 2 × (length + width) + (2 × thickness)

Standard bezel wire dimensions:

Bezel height selection:

• Low bezel (3 mm): Flat cabochons with low dome
• Medium bezel (4–5 mm): Standard cabochons
• Tall bezel (6–8 mm): High-dome cabochons, tall stones
• The bezel must be at least 1 mm taller than the stone height to fold over and grip

Worked example:

Setting an 18 × 13 mm oval cabochon in 26 ga (0.40 mm) fine silver bezel wire:

• h = (18 - 13) / (18 + 13) = 0.1613
• Perimeter ≈ π × ((18 + 13) / 2) × (1 + (3 × 0.026) / (10 + √(4 - 0.078)))
• Perimeter ≈ π × 15.5 × 1.0079 = 49.1 mm
• Add solder joint: 49.1 + (2 × 0.40) = 49.9 mm
• Add 1–2 mm safety margin: ~51 mm strip

Always cut slightly long and trim to fit — you can remove metal but you cannot add it back. File the ends flush before soldering.