Calculate indicative ore and concentrate payability.
Estimate dry tonnage, contained metal, payable metal, treatment charges, refining charges, penalties, credits and indicative net lot value from your own commercial inputs.
Methodology reviewed by Al Habtoor Resources on 21 July 2026.
Calculation inputs
Enter the commercial basis for the lot being reviewed.
Calculation trail
How concentrate payability is calculated.
Concentrate payability is the portion of contained metal that is contractually payable after the agreed assay basis, payable percentage and commercial deductions are applied. The calculator keeps each arithmetic stage visible so a buyer can compare the result with the written commercial formula.
Convert WMT to DMT
Dry mass equals wet shipment mass multiplied by one minus the moisture fraction. Moisture therefore reduces the tonnage used for the dry-basis assay calculation.
Calculate contained metal
Contained metal equals dry mass multiplied by the dry-basis assay percentage. Assay units must match the calculator input basis.
Apply payability
Payable metal equals contained metal multiplied by the contract payability percentage. The payable percentage may already reflect processing economics.
Apply adjustments
When charges are separate, the worksheet subtracts treatment, refining and penalty amounts and then adds entered credits.
Core formulas
- Dry mass
- Wet shipment mass × (1 − moisture percentage)
- Contained metal
- Dry mass × assay grade
- Payable metal
- Contained metal × payability percentage
- Gross metal value
- Payable metal × entered reference price
- Indicative net value
- Gross value − treatment charges − refining charges − penalties + credits
What the calculator includes.
The simple worksheet models one payable metal using wet shipment mass, moisture, dry-basis assay, payability and an entered price per payable tonne. It is useful for a transparent first-pass estimate when the contract already expresses processing economics through the payable percentage.
The professional mode allows several payable metals and can apply treatment charges per dry metric tonne, refining charges per payable tonne, combined penalties per dry metric tonne and combined credits per dry metric tonne. Each entered metal is calculated separately before the commercial adjustments are combined.
The tool does not retrieve prices or foreign exchange rates. Currency selection changes the displayed currency code only. Every price, payability, charge and credit must come from the user’s own approved commercial source.
Check the written agreement before relying on a result.
Actual ore and concentrate settlements can include minimum deductions, free-metal thresholds, scale-based treatment charges, quotation periods, provisional pricing, quotational adjustments, unit conversions, refining-charge tiers, impurity schedules, freight, insurance, taxes, sampling rules, umpire assays and contractual rounding. Those terms are not inferred by this calculator.
The current metal rows use percentage assay by mass and a price per payable tonne. They do not directly model precious-metal assays expressed in grams per tonne, ounces or payable units. Convert only where the written contract provides the correct conversion method.
Final calculations should use the contractually accepted wet weight, moisture result, final assay, pricing source, quotation period, payability schedule, treatment and refining terms, penalty schedule, credits and calculation order. A calculator result is not evidence of product availability, grade, origin, price or settlement acceptance.
Information to prepare before requesting a quotation.
Move from an estimate to a documented requirement.
Send the product, target grade, quantity, destination, Incoterm and available assay or specification documents. Availability, grade, origin, timing and price remain subject to written confirmation.
Payability calculator FAQ.
What does payability mean in a concentrate contract?
Payability is the contractually payable portion of contained metal. The percentage or deduction method must be taken from the written agreement rather than assumed from a general market convention.
How is wet metric tonnage converted to dry metric tonnage?
The calculator multiplies wet shipment mass by one minus the entered moisture percentage. A 1,000 tonne wet lot at 6 percent moisture produces 940 dry metric tonnes.
What is a treatment charge?
A treatment charge is an entered processing deduction applied per dry metric tonne in this worksheet. Actual contracts may use a different basis or scale.
What is a refining charge?
A refining charge is an entered deduction applied per payable tonne for each metal row in professional mode. The contractual unit and calculation basis must be verified.
Does the calculator provide live metal prices?
No. Demo values are illustrative and currency selection does not retrieve prices or perform foreign exchange conversion.
Can this result be used as a settlement statement?
No. The result is an indicative arithmetic estimate and does not replace the contract, final assay, official weighing, pricing notice, invoice or settlement statement.