Sizing gemstones when setting in a ring

[Silver Wren]

Can anyone remind me of the formula needed when sizing gemstones in a ring setting please? I always get it wrong!

[Dennis]

Can anyone remind me of the formula needed when sizing gemstones in a ring setting please? I always get it wrong!

For round stones, the circumference or length of metal required for a bezel is: 3.14 multiplied by the diameter of the stone. This is sometimes written as πd, or 2πr.

Oval stones can be treated as round, by taking the mean between the height and the width. So for a stone that is say 4x2, the diameter used is half of six. Dennis.