Jewelry Metal Weight Converter｜From Wax/Resin to Gold, Silver & Platinum

An essential online tool for jewelers, designers, and casters to accurately calculate the weight of a piece when converting from one material (like wax or 3D resin) to another (such as gold, silver, or platinum). Instantly estimate your final casting weight and determine the total metal required for a successful pour.

💡 Tool Overview

• Wide Material Selection: Convert between common prototyping materials (injection wax, hard wax, 3D resin) and a comprehensive list of precious metals, including various karats of gold (K10, K14, K18), silver alloys (925), and platinum (Pt900, Pt950).
• Dual Weight Calculation: The tool provides two critical figures: the estimated final weight of the jewelry piece itself and the total metal required for casting, which includes the sprue and button.
• Adjustable Casting Margin: Use the intuitive slider to set a percentage for your casting margin (sprue), typically between 20-40%, to ensure you melt the precise amount of metal needed.
• Real-Time Results: All calculations update instantly as you input values, allowing for quick comparisons and efficient material planning.

🧐 Frequently Asked Questions

Q. What is the "Casting Margin (Sprue)"?

A. This is the additional metal required to create the channel (called a sprue) through which the molten metal flows into the mold cavity. This extra metal, along with the "button" or base, ensures a complete fill and is cut off after casting. This tool calculates the total amount you need to melt in the crucible, including this margin.

Q. Can I use this to convert from one metal to another?

A. Yes. While the primary use is converting from a wax/resin model, you can select any material from both dropdowns. For example, you can easily calculate how much a Silver 925 piece would weigh if it were cast in K18 Gold by selecting them as the "Current Material" and "Metal to Cast," respectively.

📚 Fun Facts about Specific Gravity in Jewelry

The magic behind this converter is a scientific principle called specific gravity, which is a measure of a material's density. Every material, from wax to platinum, has a unique density. For instance, gold is about 19.3 times denser than water, while casting wax is roughly the same density as water.

This is why a wax model of a ring feels incredibly light, but its cast gold counterpart is substantially heavier, even though they are the exact same size and shape. The calculator uses the specific gravity values of the selected materials to first determine the volume of your original model (Volume = Mass / Density) and then calculates the new weight based on the target metal's density (Mass = Volume * Density). This simple but powerful formula has been a cornerstone of metallurgy and jewelry making for centuries.