What is the cut-off grade formula?

Cut-off grade = Operating cost ($/tonne ore) / (Metal price ($/unit) × Recovery × 1 tonne ore content). Below cut-off, mining is uneconomic.

What is a typical gold ore grade?

Open-pit operations: cut-off typically 0.3–0.5 g/t Au. Underground operations: 2–5 g/t Au to be economic. High-grade underground: >10 g/t Au. Bulk tonnage: 0.5–1.5 g/t Au.

Ore Grade & Cut-Off Grade Calculator

Calculate ore grade, cut-off grade, head grade, recovery, and mill feed parameters for mining feasibility assessment.

Tap constants to insert

Physical Constants Reference

Constant	Symbol	Value	Units
Speed of light	c	2.99792458×10⁸	m/s
Planck's constant	h	6.62607015×10⁻³‴	J·s
Boltzmann constant	kʙ	1.380649×10⁻²³	J/K
Avogadro's number	Nₐ	6.02214076×10²³	mol⁻¹
Gravitational constant	G	6.6743×10⁻¹¹	N·m²/kg²
Gas constant	R	8.31446	J/(mol·K)
Elementary charge	e	1.602176634×10⁻¹⁹	C
Electron mass	mₑ	9.1093837015×10⁻³¹	kg
Proton mass	mₚ	1.67262192369×10⁻²⁷	kg
Fine-structure constant	α	7.2973525693×10⁻³	dimensionless

How to use this calculator

1
Enter engineering parameters
Enter the structural dimensions, material properties, loads, pressures, or system specifications into the Ore Grade & Cut-Off Grade Calculator.
2
Select units and standards
Select the appropriate unit system (SI or Imperial) and applicable design standard (ISO, ASTM, NIST, ACI, etc.).
3
Run the calculation
Press Calculate to apply the engineering formula and compute the result.
4
Review against tolerances
Review the computed values against standard engineering tolerances, safety factors, or code-specified limits.

Formula

Result = f(load, geometry, material, safety factor)

load: Applied force, pressure, moment, or demand entered into the Ore Grade.
geometry: Dimensions, cross-section, span, or shape of the element under analysis.
material: Material properties such as yield strength, modulus, density, or conductivity.
safety factor: Design factor applied to the nominal result per the governing code or standard.
Result: Computed stress, deflection, capacity, efficiency, or design value.

Engineering results must be checked against the applicable code (ISO, ASTM, ACI, NIST, etc.) and tolerances.

Glossary and Definitions

Load: An external force, pressure, moment, or demand applied to a structure or component.
Safety factor: A design multiplier that reduces allowable stress below the nominal capacity to account for uncertainty.
Yield strength: The stress at which a material begins to deform plastically and will not return to its original shape.
Deflection: The degree to which a structural element bends under load, measured as displacement from rest.
Ore grade calculator: A key concept referenced by the Ore Grade: Calculate ore grade, cut-off grade, head grade, recovery, and mill feed parameters for mining feasibility assessment.
Cut-off grade: A key concept referenced by the Ore Grade: Calculate ore grade, cut-off grade, head grade, recovery, and mill feed parameters for mining feasibility assessment.
Mining calculator: A key concept referenced by the Ore Grade: Calculate ore grade, cut-off grade, head grade, recovery, and mill feed parameters for mining feasibility assessment.
Metal recovery calculator: A key concept referenced by the Ore Grade: Calculate ore grade, cut-off grade, head grade, recovery, and mill feed parameters for mining feasibility assessment.

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