Copper Stock Calculator
Risk-adjusted per-share NAV for copper deposits. Grade input in percent, price in $/lb. Up to four copper-price benchmarks compared side-by-side. Category and stage confidence weights applied automatically.
How It Works
- Pull deposit inputs from the company's NI 43-101 technical report — tonnage by category, grade (% Cu), recovery, opex, capex, mine life.
- Pick the study stage — PEA, PFS, or FS.
- Enter up to four copper-price benchmarks.
- Review the matrix — three NAV scenarios across every price benchmark.
Conversions
- Grade %: copper percent by weight. 1% Cu ≈ 22.05 lb/tonne.
- Tonnes: metric tonnes (2,204.62 lb).
- Price: $/lb LME or COMEX spot. Different futures markets can diverge.
Known Limitations (V1)
This calculator is a directional tool, not a replacement for a full engineering model. What it does not include:
- Corporate tax (add ~25-30% to opex for a rough proxy)
- Sustaining capex during operations — material in declining-grade operations
- Inflation adjustment — all numbers in nominal USD
- Royalty streams and NSR payments
- Debt servicing — the calculator assumes 100% equity financing
- Copper-price hedges — a hedged producer earns less upside than the spot price suggests
- Copper-only — byproduct credits (gold, silver, moly) not included. Use the polymetallic calculator for those deposits.
Do your own due diligence.
Read the company's 43-101 technical report, their most recent annual information form, and their insider-transaction filings before acting on any NAV estimate — including this one. Informational only; not investment advice. Full disclaimer →
Understanding Copper Stock Valuations
Copper NAV vs Gold NAV — Why the Numbers Behave Differently
Gold is primarily a monetary commodity; copper is primarily an industrial one. That difference shows up in how NAV math responds to price scenarios. Gold NAVs move relatively smoothly with spot-price changes because gold demand is reasonably price-inelastic. Copper NAVs are more sensitive to global manufacturing cycles and long-cycle capex decisions — a copper deposit with favorable economics at $5.00/lb can look uneconomic at $3.50/lb if the long-term price deck you use doesn't reflect the incentive price for new supply. Think about what price deck your assumption is anchored to: spot today, a multi-year trailing average, or the long-term industry incentive price around $5.00/lb.
How This Calculator Builds the Number
The math converts copper grade (percent) to recoverable pounds per tonne, multiplies by your copper price to get revenue per tonne processed, and runs a three-step DCF: revenue spread across mine life, operating costs deducted, capex subtracted, result discounted back to present value at your chosen discount rate. Resource-category confidence weights are applied to tonnage (inferred 20%, indicated 50%, measured 75%, probable 85%, proven 100%) and a study-stage haircut is applied to the final NAV (PEA 30% cut, PFS 15%, FS 0%). The result is a per-share risk-adjusted NAV at each copper price you specify.
Byproduct Credits and Why They Matter for Copper
Most large copper deposits produce meaningful gold and silver as byproducts, and the major open-pit copper porphyries (Casino, Kamoa, Cascabel) often have molybdenum credits on top. In a full feasibility study, these byproducts can contribute 15-30% of total project NPV — which means a pure-copper NAV calculation can materially underestimate the real value of a polymetallic deposit. If the company you are valuing has non-trivial gold, silver, or moly credits, use the Polymetallic Stock Calculator instead. This tool treats the project as copper-only and will give you a lower NAV than the company's published feasibility figures if byproducts are significant.
Reading the Output Matrix
Three rows, up to four columns. The gross NAV row assumes every tonne is measured-category quality with no study-stage risk — the theoretical ceiling. The category-weighted NAV row discounts for resource classification only. The stage-adjusted NAV (highlighted in gold) applies both category and study-stage haircuts — the realistic number to anchor on. Each column shows that scenario at a different copper price. The spread between columns is a direct read on how much copper-price volatility is embedded in your thesis.
Why Grade Matters More for Copper Than for Gold
Copper economics are more sensitive to grade than gold economics because copper mining is higher-tonnage and lower-margin per tonne. Moving from 0.4% Cu to 0.6% Cu (a modest grade increase) translates to a 50% increase in recoverable copper per tonne, which often makes the difference between a marginal and a robust project. When comparing copper deposits, a high-grade 0.8%+ porphyry with smaller tonnage can produce a better NAV than a lower-grade (0.3%) bulk-tonnage deposit — the opex and capex savings from processing less total rock are substantial. Use this calculator to verify those intuitions against specific deposit inputs.