Metal Content Calculator
Estimate the contained metal in an ore block from its tonnage and grade. Enter either a percent grade (for base metals such as copper, nickel or zinc) or a grams-per-tonne grade (for precious metals such as gold or silver), and the calculator returns the contained metal in the appropriate units.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the ore tonnes for the block or deposit.
- Enter exactly one grade: a percent grade for base metals, OR a grams-per-tonne grade for precious metals.
- Read the contained metal in tonnes and kilograms (percent mode) or kilograms, troy ounces and grams (g/t mode).
How it works
For a percent grade the contained metal in tonnes equals tonnes multiplied by grade percent divided by 100; multiplying by 1000 gives kilograms. For a grams-per-tonne grade the contained metal in grams equals tonnes multiplied by the g/t grade; dividing by 1000 gives kilograms and dividing by 31.1035 gives troy ounces (one troy ounce = 31.1035 grams).
Worked example
Worked example. A 500,000 t block at 1.5% copper contains 500,000 x 1.5 / 100 = 7,500 t (7,500,000 kg) of copper. A 500,000 t block at 2 g/t gold contains 500,000 x 2 = 1,000,000 g = 1,000 kg = 32,150.72 troy ounces of gold.
Common mistakes
- Entering both a percent grade and a g/t grade at once - enter exactly one.
- Mixing up the modes: percent grade is for base metals, g/t is for precious metals.
- Treating contained metal as recoverable metal - this is an in-situ figure before recovery and dilution.
Frequently asked questions
Why must I enter only one grade?
Percent and grams-per-tonne describe the same grade in different units, so the tool needs exactly one to avoid ambiguity. It shows an error if both or neither are entered.
Is this the metal I can actually sell?
No. This is contained (in-situ) metal. Actual recoverable metal is lower once mill recovery and mining dilution are applied - use a recovery and dilution tool for that.
Related tools
- Stockpile Grade Blending Calculator
- ROM Stockpile Days Calculator
- Mining Recovery & Dilution Impact Calculator
- Pit Optimisation Revenue Estimator
- Grams per Tonne to Ounces per Tonne Converter
- Net Smelter Return (NSR) Calculator
Explore more in Mining, Quarry, Earthworks, Drill & Blast.
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.