Specific Charge Calculator
Computes specific charge from charge per hole and the burden, spacing and bench volume.
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 charge per hole.
- Enter the burden, spacing and bench height.
- Press Calculate.
How it works
Specific charge (powder factor) = charge per hole ÷ the rock volume that hole breaks (burden × spacing × bench height).
Worked example
90 kg, 3×3.5×10 m. ≈ 0.086 kg/m³.
Frequently asked questions
Is specific charge the same as powder factor?
Yes — both express explosive per unit volume of rock. This tool derives it per hole.
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Explore more in Mining, Quarry, Earthworks, Drill & Blast.
Cite this tool
Zerdly. (2026). Specific Charge Calculator. Retrieved from https://www.zerdly.com/tools/specific-charge-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.