Precious Metal Weight Calculator
Convert jewellery weight from wax models or 3D printed resin to gold, silver, platinum and palladium alloys using specific gravity ratios.
How Does This Calculator Work?
Every metal has a unique specific gravity (also called density ratio) — a measure of how heavy it is relative to water. When a jeweller designs a piece in wax and casts it in different metals, the shape stays the same but the weight changes proportionally to each metal's specific gravity.
For example, if a ring weighs 5.00 g in sterling silver (SG 10.36) and you want to know what it would weigh in 18K yellow gold (SG 15.58), the calculation is: 5.00 × (15.58 ÷ 10.36) = 7.52 g. This is essential for accurate quoting, material costing, and production planning.
Wax & Resin to Metal Conversion
The most common use of this calculator is converting from a wax model or 3D printed resin prototype to the target casting metal. Standard injection wax has a specific gravity of approximately 0.97, while castable 3D printing resins typically range from 1.05 to 1.15 (we use 1.10 as a standard average). This means a 1-gram wax piece will weigh roughly 15–16 grams when cast in 18K yellow gold, or about 20 grams in platinum.
Knowing this conversion before casting allows jewellers to accurately quote material costs, estimate finished piece weight for comfort and wearability, and calculate the amount of metal needed for each production run. It is especially important when working with precious metals where even small weight differences significantly affect cost.
Why Specific Gravity Matters
Knowing the weight conversion between metals helps jewellers accurately estimate material costs before production. A piece designed in silver will weigh nearly twice as much when cast in platinum, significantly affecting the final price. Gold alloy densities vary by karat and colour — 18K white gold is denser than 18K rose gold due to the heavier alloying metals used.
Alloy & Resin Variations
Specific gravity values for gold alloys depend on the alloying metals used, and 3D printing resin densities vary by brand and formulation (Formlabs Castable Wax ≈ 1.02, B9 Emerald ≈ 1.10, Asiga SuperCAST ≈ 1.12). The figures in this calculator represent typical industry-standard values. Actual densities may vary slightly, so for critical production runs we recommend verifying with your specific alloy or resin supplier, or contacting our team for precise calculations.