Explainer
By Trent Klarenbach, BSA AgEc, PAg. Updated Oct 28, 2026
AISC, or all-in sustaining cost, is what it costs per ounce to keep a gold mine producing at its current rate. It covers site operating costs, royalties and production taxes, sustaining capital, corporate overhead, reclamation and sustaining exploration, minus by-product credits. The World Gold Council defined it in 2013 and updated it in 2018. It is a non-GAAP number that companies calculate themselves, so check the definition before you compare two of them. Gold price minus AISC is a margin, not free cash flow.
Cash cost covers the mine site. AISC adds what it takes to sustain production. All-in cost (AIC) adds growth spending on top.
AISC excludes income tax, interest and other financing charges, most working capital, and acquisition costs.
The judgment call is what counts as sustaining versus growth capital. Moving spending into growth lowers AISC.
Check whether AISC is per ounce sold or produced, consolidated or attributable, and actual or guidance.
For developers, the study's life-of-mine AISC matters less than the first three to five years.
| Cost item | In AISC? | In all-in cost (AIC)? |
|---|---|---|
| Mining, processing and site G&A (on a sales basis) | Yes | Yes |
| Royalties and production taxes | Yes | Yes |
| By-product credits (e.g. silver, copper) | Deducted | Deducted |
| Corporate G&A, including share-based pay | Yes | Yes |
| Reclamation at operating sites (accretion and amortization) | Yes | Yes |
| Sustaining exploration and studies | Yes | Yes |
| Sustaining capital, stripping and underground development | Yes | Yes |
| Growth capital and new projects | No | Yes |
| Non-sustaining exploration and studies | No | Yes |
| Income tax | No | No |
| Interest and other financing charges | No | No |
| Working capital (other than inventory adjustments) | No | No |
| Acquisitions and disposals | No | No |
Source: World Gold Council Guidance Note on Non-GAAP Metrics. Individual companies apply it, and some depart from it.
Cash cost. The cost of running the mine and plant, plus royalties, net of by-products. It ignores the capital needed to keep producing.
AISC. Cash cost plus sustaining capital, corporate overhead, reclamation and sustaining exploration. It is the cost of standing still.
All-in cost (AIC). AISC plus spending on new mines, expansions and growth exploration. It is the cost of standing still and growing.
A mine that looks cheap on cash cost can look ordinary on AISC if it needs heavy sustaining capital every year, such as an underground mine that must keep developing new levels.
A hypothetical mine sells 200,000 ounces of gold in a year.
| Line | US$ millions | US$ per oz |
|---|---|---|
| Site costs and royalties, net of by-product credits | 190 | 950 |
| Corporate G&A | 14 | 70 |
| Reclamation (accretion and amortization) | 4 | 20 |
| Sustaining exploration | 6 | 30 |
| Sustaining capital and development | 46 | 230 |
| All-in sustaining cost (AISC) | 260 | 1,300 |
| Growth capital (new pit) | 60 | 300 |
| All-in cost (AIC) | 320 | 1,600 |
At an assumed gold price of US$3,000 an ounce, the AISC margin is US$1,700 an ounce, or US$340 million. That is not what lands in the bank. Income tax, interest, the US$60 million of growth capital and any change in working capital all come out after it.
Sustaining or growth? The guidance treats costs at new operations and major projects that materially increase production as non-sustaining. Where a company draws that line is its own call, and it must disclose which projects it treats as non-sustaining.
Sold or produced. The guidance reports per ounce sold. Some companies quote per ounce produced.
Consolidated or attributable. A company with a 70% share of a mine may report costs on either basis. It should say which.
By-product prices. A copper-gold mine's AISC falls when copper rises. That is a metal price call, not efficiency.
Guidance versus actual. Compare reported AISC with the guidance the company gave at the start of the year. Repeated misses tell you something.
Developers don't report AISC yet, but their studies forecast it. A preliminary economic assessment or feasibility study usually quotes a life-of-mine AISC. Check it against the study's gold price, the first years of production, and what peers actually achieve. The PEA vs PFS vs FS guide explains how much to trust each study.
For a junior about to become a producer, the first two years of AISC often run above the study as the plant ramps up. Price that in.
Does the company say it follows the World Gold Council guidance?
Is there a reconciliation to the financial statements in the MD&A?
Per ounce sold or produced?
Consolidated or attributable basis?
Which projects are classed as non-sustaining, and did that list change?
By-product credits, and the metal prices behind them.
Actual AISC against the year's guidance.
Sustaining capital per ounce, compared with prior years.
All-in cost as well as AISC.
AISC margin after tax and interest, not just before.
Royalty and streaming companies don't carry mine costs this way. See how to evaluate a royalty or streaming company. Terms are in the glossary.
What does AISC stand for? All-in sustaining cost: the per-ounce cost of keeping a gold mine producing at its current rate, including site costs, royalties, sustaining capital, corporate G&A, reclamation and sustaining exploration, net of by-product credits.
Who defined AISC? The World Gold Council published its guidance note on all-in sustaining costs and all-in costs in 2013 and updated it in November 2018.
What is not included in AISC? Income tax, interest and other financing charges, most working capital, acquisition costs, and growth or non-sustaining capital and exploration.
What is the difference between AISC and all-in cost? All-in cost adds non-sustaining spending, such as new mines, expansions and growth exploration, to AISC.
Is AISC margin the same as free cash flow? No. AISC margin is the gold price minus AISC. Taxes, interest, growth capital and working capital changes come out after it.