Gold Mine Sustaining Capital vs. Growth Capital: What Investors Should Know
Gold-mining companies often divide capital spending into two broad categories: sustaining capital and growth, project, or development capital. The distinction matters because the two categories answer different questions. Sustaining capital helps keep an existing operation producing safely and reliably under its current mine plan. Growth capital is intended to build a new mine, expand capacity, extend a project beyond its current plan, or add a new source of production.
What counts as sustaining capital?
Sustaining capital can include replacement of mobile equipment, tailings-storage lifts, water infrastructure, plant maintenance projects, and underground development needed to reach ore already included in the operating plan. Newmont’s 2025 annual report describes sustaining capital as expenditure necessary to maintain current production and execute the current mine plan. That definition is useful, but investors should still read each company’s own policy because classification involves judgment.
The World Gold Council’s guidance on non-GAAP metrics incorporates sustaining capital into all-in sustaining cost, or AISC. The framework was designed to improve transparency around the cost of producing gold. However, AISC is not a complete measure of company cash flow: it can exclude initial mine construction, major expansions, income taxes, financing costs, and other material uses of cash.
Why growth capital sits outside AISC
Growth capital generally funds projects expected to increase production, reserves, processing capacity, or mine life beyond the current operating plan. Because this spending is usually excluded from AISC, a producer may report a healthy AISC margin while also committing substantial cash to expansion. That does not make the investment good or bad; it means investors should reconcile AISC with the full capital budget and free-cash-flow statement.
Current disclosures illustrate the difference. In its February 2026 guidance, Newmont projected about $1.95 billion of sustaining capital for tailings, water, infrastructure, equipment, and ongoing mine development, plus about $1.4 billion of development capital for selected projects. Barrick likewise reports minesite sustaining and project capital separately in its second-quarter 2026 management discussion. These disclosures show why one cost headline rarely captures total capital demand.
A simplified hypothetical example
Hypothetical example only: Assume a mine sells 100,000 ounces, incurs $120 million of operating costs, spends $30 million of sustaining capital, and invests $50 million in an expansion. Operating costs plus sustaining capital equal $150 million, or $1,500 per ounce. Including the expansion raises the simplified cash requirement to $200 million, or $2,000 per ounce. Neither figure is a formal AISC calculation, which includes additional items and adjustments, but the example shows why growth spending can materially change cash needs.
What investors should investigate
A low sustaining-capital number is not automatically positive. It may reflect efficient assets, but it can also signal deferred maintenance or a temporary lull in stripping, underground development, or tailings work. High sustaining capital may indicate aging infrastructure, deeper mining, or responsible investment in safety and environmental controls. Growth capital can create value, yet it introduces construction, permitting, funding, schedule, and ramp-up risk.
Useful due-diligence questions include: Has management defined each category consistently? Does capital reconcile with the cash-flow statement? Which spending is committed versus discretionary? What production or reserve benefit is expected, and when? How sensitive is the budget to inflation, currency, and schedule changes? Finally, compare several years rather than relying on a single period; capital programs are often lumpy.
The investor takeaway
Sustaining capital helps preserve an existing operating base, while growth capital seeks to create future capacity or value. Investors get a clearer picture by reading AISC, total capital expenditure, free cash flow, and project disclosures together—and by testing whether the promised benefit justifies the added risk.
This article is for educational purposes only and is not investment advice or an offer to buy or sell any security. Mining investments involve commodity-price, geological, operational, financing, regulatory, environmental, and political risks. Conduct independent due diligence and consult qualified advisers.