What is all-in sustaining cost (AISC)?

All-in sustaining cost is a metric, defined by the World Gold Council in 2013 and widely adopted across metals, that captures the full recurring cost of producing a unit of metal. It includes cash operating costs plus royalties, sustaining capital, and corporate overhead — but excludes growth/expansion capex and financing.

AISC is expressed per ounce (gold, silver) or per pound (copper and other base metals). Subtract it from the metal price for a rough margin: a gold miner with $1,300/oz AISC at a $2,000/oz gold price earns about $700/oz before tax and growth spending.

For investors it is the single most useful operating-cost number: it lets you compare miners and stress-test them against falling prices. A low-AISC producer survives a price downturn that wipes out high-cost peers. Caveats: definitions vary slightly between companies, AISC excludes expansion capex (which can be large), and by-product credits can flatter a primary metal's reported cost.