Research reviewed 8 November 2026 · Reference methods; checked 8 November 2026
A cargo’s gross mass is only the starting point for a copper concentrate discussion. Moisture reduces wet tonnes to dry tonnes. The dry assay gives contained copper. Contract payability then determines the metal quantity used in the simplified value calculation.
Follow the units
For an illustrative 20,000 wet tonnes at 8% moisture, dry mass is 18,400 tonnes. A 25% dry copper assay represents 4,600 tonnes of contained copper. Applying an assumed 96.5% payability produces 4,439 payable copper tonnes. These are example inputs, not terms offered by a producer or a smelter.
Treatment charges are often expressed against dry concentrate mass. Refining charges may be expressed in cents per payable pound. The calculator converts those units explicitly and displays each deduction. It accepts negative treatment or refining charges as credits so that the arithmetic does not silently impose a positive-fee assumption.
What the result leaves out
The simplified value is not profit. Real contracts may include minimum deductions, payable thresholds, assay settlement procedures, penalties, credits for other metals, freight allocation, price periods, taxes, financing and insurance. Timing and counterparty risk also matter. A dry mass and a quoted benchmark alone cannot determine the final settlement.
LME specifications describe exchange-deliverable Grade A cathode, including physical quality and brand requirements. A concentrate is not that product. A copper-equivalent calculation does not make an intermediate material exchange-deliverable.
Use the planner to prepare questions for a qualified commercial discussion. Download the assumptions with the result, and keep the actual contract and independent assay as the controlling documents.