⚖️ Metal Weight Calculator
Enter the volume of your metal piece (e.g. from a wax model or CAD file) and select a metal type to estimate its weight.
How the weight is worked out
Two multiplications, and the troy ounce conversion uses the exact figure of 31.1035 g:
grams = volume cm³ × density g/cm³
troy oz = grams / 31.1035A 2 cm³ model in 14k gold at 13.07 g/cm³ weighs 26.14 g, or 0.840 ozt. Cast the same model in sterling at 10.36 and it is 20.72 g; in platinum at 21.45 it is 42.90 g, more than twice the silver. Note the troy ounce is not the kitchen ounce - 31.1035 g against 28.3495 g, so it is 9.7 per cent heavier, and that gap lands straight in any price taken from it.
Karat, and what the tool does not do
Karat is parts of gold in 24 by mass: 14k is 14/24 = 58.33 per cent fine, 18k is 75 per cent, 24k is pure. So the 26.14 g 14k casting contains 26.14 × 0.5833 = 15.25 g of gold, 0.490 ozt, and 10.89 g of alloy. Density does not track purity, because the copper and silver added are lighter than gold: 13.07 is 68 per cent of 24k's 19.32, while the gold content is only 58 per cent.
The listed densities are typical yellow alloys. White gold with palladium and nickel-white 14k both sit away from 13.07, so treat a casting quote as the authority when the metal is white.
Frequently asked questions
How much does 14k gold weigh per cm³?
About 13.07 g for a yellow alloy. 18k runs 15.58 and pure 24k gold 19.32, so the same ring gets 19 per cent heavier moving from 14k to 18k.
How do I find the volume of my model?
Read it from the CAD file, or weigh the wax and divide by the wax density, which is near 0.9 g/cm³. A 1.8 g wax is then about 2 cm³.
How much pure gold is in a 14k piece?
58.33 per cent by weight, since 14 divided by 24 is 0.5833. A 26.14 g 14k ring holds 15.25 g of fine gold.