How the Compacted Material Converter Works
The Compacted Material Converter divides mass by tapped or compacted density, the density after vibration or pressing removes some air. The default 0.85 kg/L fits a settled powder.
Measure the compacted density
Tap a measuring cylinder 500–1,250 times, as in USP <616> and ISO 787-11, then weigh the settled powder.
Enter the mass
Type the kilograms of material.
Enter the compacted density
Type the tapped value in kg/L.
Compare with loose volume
Run the loose density too; the difference shows how far the material settles.
Compacted Material Converter Formula
The compacted volume formula is Vc = m ÷ ρtapped. Flow indices compare tapped and loose densities.
- ρtapped
- Density after tapping or compaction, kg/L
- ρbulk
- Loose poured density, kg/L
Worked Examples
- Settled powder: 25 kg ÷ 0.85 kg/L = 29.41 L, against 38.46 L loose at 0.65 kg/L.
- Hausner ratio: 0.85 ÷ 0.65 = 1.31; values from 1.26 to 1.34 rate as passable flow.
- Carr index: 100 × (0.85 − 0.65) ÷ 0.85 = 23.5%, inside the 21–25% "passable" flow band.
Compacted Material Converter Conversion Table
Tapping shrinks most powders by 10% to 35% in volume. The table compares loose and tapped densities and the volume of 25 kg (55.1 lb) in each state.
| Material | Loose (kg/L) | Tapped (kg/L) | 25 kg Loose (L) | 25 kg Tapped (L) | Hausner Ratio |
|---|---|---|---|---|---|
| All-purpose flour | 0.53 | 0.73 | 47.17 | 34.25 | 1.38 |
| Powdered sugar | 0.56 | 0.80 | 44.64 | 31.25 | 1.43 |
| Cocoa powder | 0.45 | 0.62 | 55.56 | 40.32 | 1.38 |
| Milk powder | 0.50 | 0.65 | 50.00 | 38.46 | 1.30 |
| Portland cement | 1.20 | 1.60 | 20.83 | 15.63 | 1.33 |
| Ground coffee | 0.35 | 0.45 | 71.43 | 55.56 | 1.29 |
| Dry sand | 1.60 | 1.75 | 15.63 | 14.29 | 1.09 |
| Topsoil | 1.10 | 1.45 | 22.73 | 17.24 | 1.32 |
What is a Compacted Material Converter?
A Compacted Material Converter is a calculator that finds the volume of a powder or soil after settling, vibration or compaction.
Powders shrink in volume during transport. A bag filled to the brim at the factory arrives with headspace after vibration on a truck. The tapped density predicts that settled volume.
Pharmaceutical, food and construction standards rate flow with the Hausner ratio. A ratio of 1.00–1.11 means excellent flow; above 1.60 means very poor flow.
What are the Uses of a Compacted Material Converter?
There are 4 main uses of a Compacted Material Converter.
Package headspace
Packers size cartons for the settled volume, not the poured volume.
Backfill planning
Contractors order soil and sand by compacted cubic meters.
Tablet and capsule fill
Pharma teams set die fill depth from tapped powder density.
Silo capacity
Operators rate silos for the denser, consolidated material at the bottom.