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Free STL to gold and silver weight calculator

Find out how much gold, silver, or platinum a ring or pendant takes. Read the volume from a model file, or start from the weight of your wax or resin pattern.

Runs in your browser. Your file is never uploaded.

Your model

Drop an STL, OBJ, or 3MF here.

Up to 250 MB. All processing stays on your device.

Files stay on your device.

Options

Model or pattern
Starts at 0 because investment expansion can offset shrinkage. Confirm an override with your caster. Applies to model dimensions and volume.
Wax is about 1.0 and castable resin about 1.1. Check your resin’s data sheet.
Metal and casting
Extra metal melted for the sprue and button.
Optional price
This page never looks up prices. Leave it at 0 to skip cost.

Result

Choose a model, try the example, or switch to the wax or resin mode.

How it works

  1. 1

    Pick a starting point

    Drop a ring or pendant model, or switch to the wax or resin mode and enter the pattern’s weight.

  2. 2

    Set the extras

    Choose the metal to price, the button allowance, and, if you like, a price that you type in.

  3. 3

    Read the weights

    Compare every metal in grams, pennyweight, and troy ounces. Save the report.

Typical densities
Gold colors vary by alloy, and white gold varies most. The table shows typical values and ranges. Use your refiner’s number for a quote.
Button allowance
Casting needs extra metal for the sprue and the button. The default adds 10% to the metal you melt.
Wax and resin
Metal weight is the pattern’s weight times the metal’s density, divided by the pattern’s density. Casting numbers are estimates. Ask your refiner or investment maker for burnout schedules and pour temperatures.

Questions

How do I convert wax weight to gold weight?

Multiply the wax weight by the metal’s density and divide by the wax’s density. The wax mode does this for every metal at once.

Does the price come from the market?

No. You type the price, and this page never looks one up, so nothing leaves your device.

What is the button allowance?

It is the extra metal melted so the sprue and button stay full as the casting cools. It is not part of the finished piece. The default is 10%, and you can change it.

Why does an open model give only an estimate?

Missing faces and mixed winding distort the volume calculation. The page counts open edges and labels the weights as estimates.

Is my file uploaded anywhere?

No. The conversion runs in your browser with the JavaScript on this page. Your data never leaves your computer, and nothing is kept after you close the tab.

Quoting custom jewelry?

I build pricing tools that read your CAD files and price pieces with today's metal prices.

Ask about automating itSee custom software work

Source code and license

You can inspect the code and the licenses here. Models are parsed and measured on your device.