Metal weight calculator for jewelry
Enter the metal volume from your CAD software, or the weight of a wax or resin model, to estimate what the finished piece will weigh in 9k to 24k gold, sterling silver, platinum or palladium. Results appear in grams, pennyweight and troy ounces.
Sprue or finishing, optional
Estimated weight in 18k yellow gold
The same piece in other metals
| Metal | Density g/cm³ | Weight |
|---|---|---|
| 24k gold | 19.3 | 7.72 g |
| 22k yellow gold | 17.8 | 7.12 g |
| 18k yellow gold | 15.5 | 6.20 g |
| 18k white gold | 15.0 | 6.00 g |
| 18k rose gold | 15.1 | 6.04 g |
| 14k yellow gold | 13.1 | 5.24 g |
| 14k white gold | 12.9 | 5.16 g |
| 14k rose gold | 13.0 | 5.20 g |
| 10k yellow gold | 11.6 | 4.64 g |
| 9k yellow gold | 11.2 | 4.48 g |
| Sterling silver 925 | 10.4 | 4.16 g |
| Platinum 950 with ruthenium | 20.7 | 8.28 g |
| Platinum 950 with iridium | 21.5 | 8.60 g |
| Palladium 950 | 12.0 | 4.80 g |
Densities are typical values and real alloys vary with their recipe, especially white golds. Measure the volume of metal parts only, without stones. For quotes and casting, use the density figures supplied by your caster.
How to use the calculator
Choose From CAD volume if you have a 3D model. Most jewelry CAD programs can report the volume of a closed solid, often in cubic millimetres. Enter that number, choose the unit and pick a metal. The calculator multiplies the volume by the metal's density and shows the weight in grams, pennyweight and troy ounces, plus a table of the same piece in every other metal.
Choose From a wax or resin model if you have a physical model for casting. Weigh it in grams, pick the model material and the calculator works out its volume, then the weight in metal. If you know the exact density of your wax or resin, choose Custom density and enter it.
The optional Extra allowance % adds a percentage on top, for example to estimate the metal needed for casting, including sprues, rather than the finished weight.
The formula
Weight equals volume multiplied by density. With volume in cubic centimetres and density in grams per cubic centimetre, the result is in grams. One cubic centimetre is 1,000 cubic millimetres, so a ring with a volume of 400 mm³ has a volume of 0.4 cm³. In 18k yellow gold, at about 15.5 g/cm³, it weighs about 6.2 grams.
For a wax model, the volume is the model's weight divided by the wax density. Carving and injection waxes are close to 1 g/cm³, so a quick rule of thumb is to multiply the wax weight by the density of the metal. Castable resins are a little denser, often around 1.1 to 1.2 g/cm³, but this varies by brand.
Typical densities
| Metal | Approx. density in g/cm³ |
|---|---|
| 24k gold | 19.3 |
| 22k yellow gold | 17.8 |
| 18k yellow gold | 15.5 |
| 18k white gold | 15.0 |
| 18k rose gold | 15.1 |
| 14k yellow gold | 13.1 |
| 14k white gold | 12.9 |
| 14k rose gold | 13.0 |
| 10k yellow gold | 11.6 |
| 9k yellow gold | 11.2 |
| Sterling silver 925 | 10.4 |
| Platinum 950 with ruthenium | 20.7 |
| Platinum 950 with iridium | 21.5 |
| Palladium 950 | 12.0 |
These are typical figures. Real alloys vary with their recipe, especially white golds, which can be made with nickel or palladium and differ noticeably in density. For quotes and casting, use the densities your caster or refiner supplies.
Weight units jewelers use
- Grams are the everyday unit in most countries and in most CAD software.
- Pennyweight (dwt) is common in the US jewelry trade. One pennyweight is about 1.555 grams, and 20 pennyweight make one troy ounce.
- Troy ounces (ozt) are used to price precious metals. One troy ounce is about 31.10 grams, heavier than the everyday ounce of about 28.35 grams.
Tips for accurate volumes
- Measure metal only. Hide or remove stones before measuring, since their volume would otherwise be counted as metal.
- Use a closed model. Volume can only be measured reliably on a closed solid. Open edges or overlapping parts give wrong results. See watertight mesh.
- Check hollow parts. Galleries, under-bezels and pierced work remove a lot of metal. Make sure the model matches the piece you will cast.
Why weight matters early
Metal weight drives cost, comfort and how substantial a piece feels in the hand. Knowing it at the design stage helps you price a piece, choose between metals and avoid surprises when the casting comes back. A heavier shank may feel more luxurious but adds cost in every metal, while a hollowed gallery can save weight without changing the look from the front.
The same CAD file that gives you the volume can also be rendered for customers. With RenderMyJewels you can show the design in every metal before it is cast and start taking orders at the same time. See sell jewelry before casting.