Net Smelter Return (NSR) Calculator
Net Smelter Return is the revenue an operation actually banks per tonne of ore after the smelter, refinery and freight take their cut.
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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 grade (g/t), the metallurgical recovery (%) and the metal price per gram of payable metal — keep the price in the same metal and mass unit as the grade.
- Optionally add payability (%) and the per-tonne treatment, refining and transport charges; leave any blank to treat it as 100% payable or a zero deduction.
- Read the NSR in $/t of ore — the revenue left after payability and off-site charges, ready to compare against your cost per tonne and cutoff grade.
How it works
Net Smelter Return is the revenue an operation actually banks per tonne of ore after the smelter, refinery and freight take their cut. The tool works entirely from unit-consistent inputs: NSR ($/t ore) = grade x recovery x price x payability − (treatment + refining + transport). Grade x recovery gives the metal you recover per tonne; multiplying by payability strips off the fraction the smelter does not pay for; multiplying by the metal price converts grams to dollars; then the fixed per-tonne charges are subtracted.
Because grade is in grams per tonne and price is dollars per gram, the product is already dollars per tonne of ore, so the deductions (also $/t ore) subtract cleanly. Recovery and payability are entered as percentages and converted to fractions internally. The formula generalises to any metal and unit as long as the price is quoted per unit of the same payable metal as the grade — for a copper grade in % you would price per unit of contained metal accordingly. This is a planning estimate only: real smelter contracts add penalty elements, minimum deductions, moisture and price-participation terms.
Worked example
Gold ore at 5 g/t. A gold ore runs 5 g/t at 90% metallurgical recovery, a payable gold price of $60/g and 98% payability. Treatment, refining and transport add $8 + $2 + $5 = $15/t. Payable metal = 5 x 0.90 x 0.98 = 4.41 g/t. Payable revenue = 4.41 x $60 = $264.60/t. NSR = $264.60 − $15.00 = $249.60 per tonne of ore. That $249.60/t is the revenue available to cover mining, processing, G&A and margin — the number a breakeven cutoff grade is built from.
Common mistakes
- Mixing units between grade and price — the grade is g/t and the price must be per gram of the SAME payable metal. Feeding a $/troy-ounce price against a g/t grade without converting (1 troy oz = 31.1035 g) inflates the result ~31x.
- Confusing recovery with payability. Recovery is the metallurgical fraction that reports to concentrate; payability is the fraction of that metal the smelter actually pays you for. They are separate multipliers and both belong in the NSR.
- Leaving out the off-site deductions and treating gross in-situ revenue as NSR. NSR is a NET figure — the treatment, refining and transport charges must be subtracted before you compare it to your cost per tonne.
Frequently asked questions
What is Net Smelter Return (NSR)?
NSR is the revenue an operation receives per tonne of ore (or per tonne of concentrate) after the smelter and refinery deduct their treatment and refining charges and after transport/freight. It is the payable value of the recovered metal minus the off-site costs, and it is the basis for royalties, cutoff grades and mine-plan revenue.
How is NSR different from gross revenue or head value?
Gross in-situ (head) value is simply grade x recovery x price — the value of the metal you recover before anyone takes a cut. NSR subtracts payability losses and the treatment, refining and transport charges, so it is always lower than gross revenue and is what actually reaches the mine's bank account.
Can I use this for copper, silver or any other metal?
Yes. Keep the price in the same metal and mass unit as the grade. For a gold ore use g/t and $/g; for a metal quoted in ounces convert the price to $/g first (divide $/troy oz by 31.1035). The formula itself is metal-agnostic.
Why is my NSR negative?
A negative NSR means that at the entered grade, recovery, price and payability the payable revenue is smaller than the treatment, refining and transport charges — the ore cannot even cover its own off-site costs, so it sits below any economic cutoff grade.
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- Breakeven Cutoff Grade Calculator
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