Work out ore grade instantly with clear inputs, formula shown and shareable results.
Ore grade is contained metal as a percentage of ore mass, or grams per tonne for precious metals where 1% equals 10,000 g/t. What matters commercially is recoverable value per tonne — grade times price times metallurgical recovery — because that is what must cover mining and processing cost.
Ore grade
Grade % = contained metal x 100 / ore tonnage; g/t = grade % x 10,000
Recoverable value
Value per tonne = grade x recovery x metal price
Convention follows value density: percent for base metals such as copper and zinc, grams per tonne for gold and platinum, and parts per million or ounces per ton in some jurisdictions. Always state the unit.
Entirely dependent on metal price, depth, recovery and scale. Open-pit copper at 0.3% can be economic at large scale while underground gold below 3 g/t often is not.