What Is AISC? All-In Sustaining Cost Explained

AISC Is a Cost, and It Still Leaves Spending Out

All-In Sustaining Cost is the per-ounce figure producers quote in earnings releases and the number investors use to rank mines on the cost curve. It is a cost, not a margin: the margin is what is left when you take AISC off the gold price. It runs well above cash cost because it adds the capital and overhead a mine needs simply to keep going at its current rate.

The World Gold Council (WGC) published its AISC guidance in 2013. It has since displaced cash cost as the standard peer-comparison metric, because it tracks what actually happens to a miner’s economics when gold prices move.

The World Gold Council Definition

The WGC defines AISC as everything a mine has to spend to hold production where it is, expressed per ounce of gold produced:

AISC ($/oz) = (Cash Costs + Sustaining CapEx + Sustaining Exploration + Reclamation Accretion and Amortisation + Corporate G&A) / Gold Ounces Sold

That is roughly the revenue per ounce a mine needs to keep running as it is. It is not the full cost of being in the gold business: tax, interest, the hunt for new deposits, and the capital to build or expand a mine all sit outside it, in the wider all-in cost. For a step-by-step guide to pulling these figures from annual reports, see How to Calculate AISC from Financial Statements.

What Goes Into AISC

Cash Operating Costs

Cash operating costs include all direct costs of mining, concentrating, smelting, and refining gold. This encompasses:

• Direct mine labour and contractor crews
• Diesel, explosives, and consumables
• Grinding media and reagents
• Maintenance and repairs to mine equipment
• All metallurgical processing to convert ore into doré bars
• Royalties and production taxes paid on the metal sold

For a typical open-pit gold mine, cash operating costs run somewhere around $750 to $1,100 per ounce, depending on ore grade, local wages, and the strip ratio, which is how many tonnes of waste rock have to be moved for every tonne of ore. High-grade operations in developed jurisdictions can come in nearer $650/oz; low-grade operations in remote locations with heavy logistics costs run past $1,400/oz.

Sustaining Capital Expenditure

Sustaining CapEx comprises all capital invested to maintain production at current rates. It excludes expansion or new mine development, but includes:

• Pit mobile equipment replacement and upgrades
• Mill and plant rebuilds and refurbishment
• Infrastructure maintenance (roads, power, water systems)
• Environmental remediation required to operate the mine
• IT systems and safety equipment

Sustaining CapEx typically accounts for $250–400 per ounce of production, though mines with ageing fleets or harsh climates (Alaska, Arctic regions) may run $500/oz or higher.

Sustaining Exploration

Exploration splits in two, and only one half counts. Near-mine drilling that replaces the reserves being consumed belongs in AISC, because without it the mine runs out. Greenfield exploration and studies aimed at new deposits do not, because they buy growth rather than continuity. Companies draw the line in different places and some keep all exploration out, so this is one of the first things to check when two AISC figures look far apart.

Reclamation at Operating Mines

Closing a mine costs money, and the obligation builds up while the mine is still running. AISC picks up the accretion and amortisation on that obligation at operating sites, spreading the eventual bill across the ounces that create it. What it does not pick up is cash spent rehabilitating mines that have already closed. A company with a long tail of shut sites can be writing real reclamation cheques that never appear in any AISC figure it reports.

Corporate G&A

Corporate general and administrative expenses include:

• Head office salaries and overhead
• Audit and compliance costs
• Insurance (including mine rehabilitation bonds)
• Professional services (legal, geological consulting)
• Investor relations and public company costs

Corporate G&A belongs to the group rather than to any one pit, so it is spread across total ounces sold instead of charged to a mine. That is why the per-mine AISC figures a company publishes usually leave it out. A large, diversified miner adds $50–150/oz at group level; a single-asset junior carries $150–250/oz, because the same head office is spread over far fewer ounces.

Typical AISC Ranges by Mine Type

The components below add roughly to the AISC above them. They are indicative ranges, not a formula, so a real mine will sit anywhere inside them.

Tier-1 Operating Mines (established, efficient, low-cost jurisdictions like Australia, Canada):

• AISC: $1,100–1,400/oz
• Cash costs: $750–950/oz
• Sustaining CapEx: $250–350/oz
• Corporate G&A: $80–120/oz

Mid-tier Mines (solid operations in Chile, Peru, or developed regions):

• AISC: $1,400–1,650/oz
• Cash costs: $950–1,100/oz
• Sustaining CapEx: $350–450/oz
• Corporate G&A: $100–150/oz

Junior/High-Cost Operations (remote locations, ageing infrastructure, emerging jurisdictions):

• AISC: $1,650–2,100/oz
• Cash costs: $1,100–1,300/oz
• Sustaining CapEx: $400–550/oz
• Corporate G&A: $150–250/oz

Why AISC Matters for Margin Analysis

Operational leverage in gold mining shows up in the gap between spot and AISC. Once gold price exceeds AISC, every additional dollar per ounce flows to operating cash flow and free cash flow (after non-sustaining CapEx and exploration).

Take a mine with $1,100/oz AISC producing 500,000 oz a year, and run it at two gold prices. The pair below is chosen to show the leverage, not to predict a price. Our valuation walkthrough uses a more conservative $3,500/oz, and the arithmetic works the same way at any level.

Scenario 1: Gold at $5,000/oz

• Margin per ounce: $3,900
• Annual operating cash flow: $1,950 million (before taxes)

Scenario 2: Gold at $4,000/oz

• Margin per ounce: $2,900
• Annual operating cash flow: $1,450 million (before taxes)

A 20% fall in the gold price takes 26% off the cash flow. The cost base barely moves, so almost the whole price change lands on the margin. That is the leverage, and it is what makes AISC central to valuation sensitivity.

Cost Curve Positioning

The global gold cost curve ranks every producer by AISC, from lowest to highest:

See the AISC Benchmarks page for current producer rankings and regional cost breakdowns.

• Quartile 1 (bottom 25%): AISC below ~$1,413/oz. Large open-pit mines in Tier-1 jurisdictions with high-grade ore.
• Quartile 2: AISC $1,413-1,709/oz. Mid-tier, efficient underground or lower-grade open-pit operations.
• Quartile 3: AISC $1,709-1,982/oz. Older or remote operations, or underground mines in marginal jurisdictions.
• Quartile 4 (top 25%): AISC above ~$1,982/oz. Marginal, high-risk, or distressed operations.

Investors often avoid Quartile 4 mines outside of bull markets, as they offer minimal margin safety and first-loss positions in downturns.

AISC vs. Cash Costs: What Gets Left Out

Cash cost is still used as a proxy for a mine’s economics, and on its own it flatters them: it ignores the sustaining capital and the head office. See AISC vs Cash Cost for a full breakdown of what each metric captures and when cash cost is still useful.

A mine quoting $700/oz cash costs might have $1,200/oz AISC once sustaining CapEx of $350/oz and corporate G&A of $150/oz are added. Press releases lead with the lower number for a reason. Always check the AISC.

Adjustments and Comparability Issues

When comparing AISC between companies, watch for:

• Exploration inclusion: the WGC line is that near-mine exploration to replace reserves belongs in AISC and greenfield exploration does not. Companies draw that line in different places, and some keep all exploration out.
• Royalty treatment: a royalty is a cost line and sits inside AISC. A stream is usually booked as metal sold at a fixed low price rather than as a cost, so it never reaches AISC at all. A streamed mine can show a respectable AISC while a slice of its output is going out of the door for a fraction of the market price. This matters most when reading royalty and streaming companies alongside the mines that pay them.
• Rehabilitation: reclamation at operating mines is inside AISC as accretion and amortisation, and cash spent on closed sites is outside it. Two companies with the same mines and different closure histories are not comparable on AISC alone.
• By-product credits: Copper, silver, or other metals produced alongside gold reduce reported AISC. A polymetallic mine’s AISC may appear artificially low due to by-product credits.

When building a valuation model, standardise AISC across a peer group by ensuring consistent treatment of these items.

Inflation and Commodity Cycle Impact

AISC is sensitive to labour costs, energy prices, and consumables. The 2021–2025 period pushed industry median AISC from roughly $1,000/oz to approximately $1,709/oz (WGC/Metals Focus, Q4 2025), driven by labour shortages, diesel costs, and royalty payments linked to higher gold prices. Mines that looked comfortable at 2020 cost levels now sit in Quartile 3 or 4.

Conversely, in commodity downturns, cash costs can fall sharply (lower fuel costs, deferred maintenance), but sustaining CapEx often remains sticky or increases (as companies catch up on deferred investment).

Connecting AISC to Valuation

In a discounted cash flow (DCF) valuation, AISC is the primary driver of operating cash flow. The valuation formula follows:

Annual FCF = (Gold Price − AISC) × Production Volume × (1 − Tax Rate)

How far an AISC error moves the valuation depends entirely on the margin it eats into. On a mine earning $2,000/oz, a 5% rise in a $1,500/oz AISC costs $75 an ounce, under 4% of the value. On a marginal mine earning $500/oz, that same $75 is 15%. The thinner the margin, the more a small cost miss matters, which is why AISC is the assumption to stress first on a high-cost asset and the discount rate usually matters more on a low-cost one.

Model the cost line as rising, not flat. Mature operations creep at roughly 2–3% a year as grades fall and equipment ages.

When a Miner Omits AISC

Cash cost alone hides sustaining capital and overhead, which together can add $400–600/oz to the real cost of production. If a miner won’t give you an AISC number, that’s usually because they don’t want you to see it.