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Powder factor
Type the pattern and the charge. The panel shows kilograms per metre, kilograms per hole and the powder factor by volume and by mass, as you type.
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How it works and what it assumes
Charge per metre is the volume of a cylinder of the hole diameter, one metre long, times the explosive density: π × d² ÷ 4 × density. A 102 mm hole of a 1.15 g/cm³ product holds about 9.4 kg per metre.
Charge per hole is that figure times the charge length. Rock per hole is burden × spacing × bench height, in bank cubic metres (before swell). Powder factor is the first divided by the second; multiply by rock density to get it in kg/t.
Powder factor is a single-hole, geometric figure. It says nothing about distribution, timing, confinement or whether the explosive was where the design put it. Read the explanation before you compare one number with another.
Read the explanation
What powder factor means, and what it does not
The number everyone quotes, what it actually measures, and the three things it hides.
Read about What powder factor means, and what it does not
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