Material planning guide
Loose vs Compacted Aggregate: Avoid Double Allowances
The measured finished layer and the delivered loose material are different quantities. Use one explicit conversion from the first to the second, then use a compatible loose density when converting to weight.
Reviewed September 6, 2026Apply the allowance to the correct volume
For 1,000 ft² at a 4-inch finished depth, the geometric volume is 333.333 ft³, or 12.346 yd³. An illustrative 15% loose-volume allowance gives 14.198 yd³ to source.
One finished quantity, different stated allowances
These are scenarios, not prescribed compaction factors.
| Finished volume | Allowance | Loose volume |
|---|---|---|
| 10 yd³ | 0% | 10 yd³ |
| 10 yd³ | 10% | 11 yd³ |
| 10 yd³ | 15% | 11.5 yd³ |
| 10 yd³ | 20% | 12 yd³ |
Do not combine incompatible densities
If a supplier supplies a direct number of tons per finished area and depth, that figure may already incorporate their compaction assumptions. Adding your own loose-volume factor again can inflate the order. Ask what state and moisture condition the density describes.
Keep the purchase increment separate
After calculating the needed loose material, round to the supplier’s order increment or minimum. This is a commercial constraint, not a compaction factor. Record both assumptions so a later quote can be compared against the same quantity basis.
Sources and product references
- Mulzer Crushed Stone — aggregate calculator
Supplier context for material-dependent bulk density and estimating limits.
- NIST — SI units: volume
Unit relationships; supplier product coverage and prices remain separate inputs.