Free Online Stripping Ratio Calculator: Breakeven Waste to Ore

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Each tonne of ore earns a margin after its own mining, processing, and overhead costs. That margin, divided by the waste mining cost, is the breakeven stripping ratio: the most waste each ore tonne can pay to remove. The pit design's actual waste-to-ore ratio must sit below it.

The waste you move to reach the ore

An open pit spends most of its life mining rock it will throw away. The stripping ratio, waste tonnes per ore tonne, is the number that decides whether that is affordable. The tool above computes the ore's recovered value from grade, price, and recovery, subtracts the ore's own mining, processing, and overhead costs to get a margin per tonne, and divides by the waste mining cost. That is the breakeven stripping ratio: the most waste each ore tonne can pay to remove. Your pit design's actual ratio is compared against it for a verdict.

Open pit cross section with ore body at the bottom and waste on the flanks that must be stripped, illustrating the waste to ore stripping ratio
An open pit is economic while waste-to-ore stays below the breakeven stripping ratio.

This completes the Mining and Resource Suite: grades from the compositing tool, the deposit from the grade-tonnage curve, the economic line from the cutoff tool, and the pit-scale test here.

What moves the verdict

  • Grade leverage is enormous: at the demo numbers, each extra 0.1 g/t adds about 7 dollars of margin per tonne, which buys nearly two more tonnes of stripping.
  • Wall angles are geotechnical money: a few degrees steeper means dramatically less waste for the same ore, which is why pit slope studies pay for themselves.
  • The instantaneous ratio climbs as pits deepen: early benches strip little, final pushbacks strip the most, and the breakeven test is what ends the deepening.
  • A failing verdict is not always fatal: phased pushbacks, higher cutoffs, or underground continuation are all answers to unaffordable strip.

What this tool is for

Screening open pit concepts, understanding why pits end where they do, and connecting pit geometry to the same margin arithmetic that sets cutoff grade. Full pit optimization runs this same test on millions of blocks; the logic per block is exactly this.

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