To calculate the length of Wire required for a Bangle:
Add the thickness of the wire you are using to the Inside Diameter, then multiply by Pi (3.1416)
63mm I.D from 3.0mm Round Wire
63 (the I.D) + 3 (the wire thickness)
66.0 x 3.1416 = 207.35mm therefore length required is approximately 210mm
To convert from one alloy to another
divide weight by the known alloy density and then multiply by wanted alloy density.
A ring weighing 3.0 grams in Stg wanted in 18ct Yellow.
3 / 10.4 x 15.5 = 4.5 grams
use our ALLOY DENSITY TABLE
Plate Area - Weight
LENGTH(mm) x WEIGHT(mm) x THICKNESS(mm) x ALLOYS DENSITY / 1000
Stg Silver Plate
100mm x 120mm x0.8mm
100 x 120 x 0.8x 10.4 / 1000 = 99.84 grams