[3] The Hausner ratio is not an absolute property of a material; its value can vary depending on the methodology used to determine it.
The Hausner ratio is used in a wide variety of industries [4][5][6][7][8] as an indication of the flowability of a powder.
The Hausner ratio (H) is related to the Carr index (C), another indication of flowability, by the formula
Both the Hausner ratio and the Carr index are sometimes criticized, despite their relationships to flowability being established empirically, as not having a strong theoretical basis.
Use of these measures persists, however, because the equipment required to perform the analysis is relatively cheap and the technique is easy to learn.