AISC vs Cash Cost: What Gold Miners Include (and Hide)

Two Metrics, Very Different Stories

Gold miners report two cost figures for the same ounce, and they can differ by half. Cash cost is what the mine spends to pour the metal. AISC (All-In Sustaining Cost) is what the company spends to still be pouring it in five years’ time. Everything sitting between the two is what stops production declining, which is why the second number does more work in a valuation than the first.

Cash cost has been around for decades. AISC was introduced by the World Gold Council in 2013 because cash cost alone was giving investors an incomplete picture. Understanding what each metric captures (and what it leaves out) is basic due diligence for anyone analysing mining equities.

What Cash Cost Includes

Cash cost covers the direct expenses of getting gold out of the ground and into saleable form:

• Mining costs: drill, blast, load, haul
• Processing costs: crushing, grinding, flotation, leaching to produce concentrate or doré
• Refining costs: smelting and refining to produce finished gold bars
• On-site G&A: mine management, safety, site administration
• Royalties and production taxes: government payments tied to production volume or revenue

For a typical open-pit gold mine in a Tier-1 jurisdiction (Australia, Canada, Nevada), cash costs run $600-900 per ounce. Underground operations skew higher, typically $800-1,100/oz, because of ore access costs, ventilation, and ground support.

Cash cost is a snapshot of mine-site operating efficiency. It does not capture any of the capital or corporate costs required to sustain that production over time.

What AISC Adds

AISC starts with cash cost, then layers on everything else needed to keep producing at current rates:

Sustaining capital expenditure covers the capital spent maintaining existing operations: equipment replacement, mill refurbishments, tailings dam raises, underground development to access new stopes. This is not growth capital (new mines, expansions). It is what the company must spend just to stop production from declining. Sustaining capex typically adds $150-400/oz depending on mine age and complexity.

Corporate G&A captures head office costs allocated to each mine. Executive salaries, audit fees, investor relations, insurance, legal. For a large diversified miner like Newmont with multiple operations, the per-ounce allocation might be $50-100/oz. A single-asset junior producing 100,000 oz/year could be paying $150-250/oz because the same fixed overhead is spread across fewer ounces.

Reclamation and remediation provisions cover mine closure and environmental rehabilitation. Miners accrue these costs over the mine life and include them in AISC. Typically $20-60/oz.

Near-mine exploration is the exploration spending required to replace reserves as they are mined. The WGC guidance says to include exploration that sustains current reserve life, but exclude greenfield or discovery-stage exploration. In practice, treatment varies between companies, which creates comparability issues.

The Gap in Practice

Here is what the cash-cost-to-AISC bridge looks like for a mid-tier gold producer:

Component	$/oz
Cash operating cost	$750
Royalties and production taxes	$120
Total cash cost	$870
Sustaining capital	$280
Corporate G&A	$110
Reclamation provisions	$40
Near-mine exploration	$50
AISC	$1,350

The gap here is $480/oz, or 55% above cash cost. With gold near $4,500/oz, a mine quoting $870/oz cash cost looks extremely profitable, and on an operating basis it is. The $1,350/oz AISC says how much of that cash goes straight back into holding production flat. Where the two figures genuinely part company is on the way down: at $1,500 gold this mine still clears its cash cost by $630/oz, but only $150/oz over AISC, which leaves almost nothing once it has paid to keep itself going.

Why the Distinction Matters for Investors

A company reporting $700/oz cash cost and $1,400/oz AISC is spending $700/oz on sustaining items. That is a capital-intensive operation. Compare it to a peer with $800/oz cash cost but only $1,100/oz AISC. The second mine has higher direct costs but lower sustaining requirements, meaning more of its cash flow is genuinely free.

The ratio of AISC to cash cost is itself a signal:

• AISC/Cash Cost below 1.3x: Low sustaining burden. Young mine with new equipment, or well-maintained operation with modest capex needs.
• AISC/Cash Cost 1.3-1.6x: Typical range for mid-life operations.
• AISC/Cash Cost above 1.6x: Heavy sustaining burden. Ageing fleet, aggressive underground development, or high corporate overhead per ounce. Worth investigating why.

When Cash Cost Is Still Useful

Cash cost still has its uses, particularly for mine-level comparisons where corporate allocation would distort the picture.

Comparing operations within the same company. If Newmont reports Boddington (Australia) at $750/oz cash cost and Ahafo (Ghana) at $950/oz, that tells you which mine site runs more efficiently before corporate overhead muddies the picture. AISC includes allocated G&A, which varies by how the company chooses to allocate; cash cost strips that out.

Short-term margin analysis. If gold falls $200/oz tomorrow, the question of whether the mine keeps running turns on cash cost, not AISC. Sustaining capex can be deferred for a quarter or two, at the cost of future production. Cash cost is the short-run break-even; AISC is the one that has to be cleared year after year.

Screening for operating leverage. Mines with low cash cost but high AISC have the most room to cut sustaining spend in a downturn. That flexibility is a double-edged sword, though, because deferred maintenance eventually shows up as production declines.

How Companies Use Cash Cost to Look Cheaper

A few common patterns show up in earnings releases and investor presentations:

Leading with cash cost in headlines. A press release titled “Cash Costs of $650/oz” sounds great. The AISC of $1,400/oz buried in the table three pages later tells the real story.

Reclassifying sustaining capex as growth capex. If a company shifts spending from “sustaining” to “expansion” or “growth” categories, AISC drops without any actual change in efficiency. Check whether total capex is rising while AISC is falling, that is usually reclassification at work.

By-product credit games. Polymetallic mines (gold plus copper, silver, or zinc) subtract by-product revenue from costs. A gold-copper mine might report $400/oz cash cost after copper credits. If copper prices fall 30%, that cash cost jumps to $650/oz overnight. Always check what commodity assumptions underpin the by-product credits.

Excluding specific items. Some companies report “adjusted AISC” that excludes one-off items like a tailings dam repair or a legal settlement. Some of those exclusions are legitimate one-offs. Others show up every single year under a different name.

Standardising for Peer Comparison

When building a peer comparison, standardise both metrics:

1. Confirm whether cash cost includes or excludes royalties (some companies strip them out)
2. Check by-product credit assumptions; restate at consistent commodity prices if needed
3. Verify that sustaining vs growth capex splits are reasonable (compare to peers)
4. Use AISC as the primary metric for margin and valuation analysis
5. Use cash cost as a secondary check on mine-site efficiency

The AISC benchmarks page shows where specific producers sit on the global cost curve, which gives you a reference point for whether a company’s reported AISC is genuinely competitive or just creatively categorised.

Which Metric to Use in Your Analysis

For DCF valuations, reserve life assessments, and discount rate selection, AISC should be the primary cost input. It captures the full sustaining cost base that a mine needs to fund to keep producing. Cash cost is the better metric for comparing individual mine sites within a portfolio, or for gauging short-term break-even levels if gold prices fall sharply.