Mine Life Calculator
Mine life (life of mine, LOM) is the simplest planning ratio in mining economics: how many years the operation can run before the reserve is exhausted.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the total mineable reserve in tonnes (the ore you can actually extract, from your reserve statement — not the in-situ resource).
- Enter the planned annual production rate in tonnes of ore per year.
- Optionally add a mining recovery/extraction % (defaults to 100%) and a dilution % (defaults to 0%) to adjust the tonnes that report to the mill, then read the mine life in years and months.
How it works
Mine life (life of mine, LOM) is the simplest planning ratio in mining economics: how many years the operation can run before the reserve is exhausted. In its base form, Mine life = mineable reserve ÷ annual production rate. Both must be in the same tonnage unit so the units cancel and leave years.
This calculator optionally refines the feed tonnes before dividing. Recoverable ore = reserve × recovery%, since not all in-place ore is extracted, and Feed tonnes = recoverable × (1 + dilution%), since waste rock mined with the ore adds tonnes to the mill feed. Mine life = feed tonnes ÷ annual production. The result assumes a constant, steady-state production rate and ignores ramp-up, ramp-down, stockpiles and grade-driven scheduling, so treat it as a first-order estimate.
Worked example
12.5 Mt reserve mined at 1.5 Mt/year. A deposit has a mineable reserve of 12,500,000 tonnes and the operation is scheduled to produce 1,500,000 tonnes of ore per year, at 100% recovery and 0% dilution. Mine life = 12,500,000 ÷ 1,500,000 = 8.33 years (about 100.0 months). If you instead apply 92% mining recovery and 8% dilution, the feed tonnes become 12,500,000 × 0.92 × 1.08 = 12,420,000 t, giving a mine life of 8.28 years.
Common mistakes
- Using the in-situ resource instead of the mineable reserve — resources include material that is not economically or physically extractable, which overstates mine life. Always start from the reserve figure.
- Mixing tonnage units (e.g. reserve in tonnes but production in kilotonnes or Mt). Convert both to the same unit before entering them or the years will be off by orders of magnitude.
- Treating the answer as a firm schedule. It assumes flat annual production with no ramp-up or ramp-down; real life-of-mine plans stagger production and will differ.
Frequently asked questions
Is mine life based on reserves or resources?
Use mineable reserves — the tonnes you can actually and economically extract. Resources include inferred and uneconomic material that should not be counted toward production, so using resources overstates the mine life.
How do recovery and dilution change the result?
Mining recovery reduces the tonnes you get out (recovered = reserve × recovery%), while dilution adds waste tonnes to the mill feed (feed = recovered × (1 + dilution%)). Both change the total feed tonnes divided by the annual rate. If you leave them blank the tool assumes 100% recovery and 0% dilution.
Does this account for ramp-up, stockpiles or a declining grade?
No. It is a simple steady-state estimate that divides total feed tonnes by a constant annual production rate. A real life-of-mine plan will schedule ramp-up, ramp-down, stockpile draw-down and grade sequencing, so use this as a first-pass figure only.
Related tools
- Strip Ratio Calculator
- Mining Rate Calculator
- Cost per Tonne Calculator
- Breakeven Cutoff Grade Calculator
- Net Smelter Return (NSR) Calculator
- Ore Waste Ratio Calculator
Explore more in Mining, Quarry, Earthworks, Drill & Blast.
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.