REFERENCE / 02
Volume, weight and bags.
Volume describes occupied space. Mass describes how much material is present. A supplier’s loose bulk density connects them for the particular product and condition.
Cubic units describe the same space
| Quantity | Equivalent |
|---|---|
| 1 yd³ | 27 ft³ = 0.764554857984 m³ |
| 1 ft³ | 0.028316846592 m³ |
| 1 m³ | 1,000 L |
| 1 US short ton | 2,000 lb = 907.18474 kg |
| 1 metric tonne | 1,000 kg |
A cubic yard is not a square yard. Multiply area by depth expressed in compatible length units before converting the resulting volume. Do not shorten either mass unit to an ambiguous “ton.”
Use loose bulk density, with a source
Required mass = loose volume requirement × loose bulk density
Bulk density includes the voids between particles. Solid particle density and specific gravity are not substitutes. Product grading, moisture and material state can change the value. Ask for the quoted product’s loose bulk density and record the source, date and condition.
A name such as sand, pea gravel, river rock or crusher run cannot supply that value reliably on its own. Tallyspan deliberately provides no automatic density table. Different offers may use different documented product densities; the override stays with its offer.
For illustration only: 4.536 m³ × 1,600 kg/m³ = 7,257.6 kg, or 7.2576 metric tonnes. The density is an example, not a recommendation.
Finished volume is a different stage
Loose before allowance = already-loose volume + K × finished volume
K states how much loose volume is needed per unit of finished volume. A 20% extra volume relative to the finished amount gives K = 1.20. A 20% reduction relative to the starting loose volume gives K = 1 ÷ 0.8 = 1.25. Ask which definition the supplier means.
Already-loose sections are never multiplied by K. Explicit K = 1 means no conversion is modeled. Extra allowance is entered separately and applied once after that conversion.
Read the package label
A volume-labeled bag can be calculated directly: 11 ft³ ÷ 0.5 ft³ = 22 bags. A 50 lb bag needs a relevant density before it can be connected to a measured volume. “Bulk bag” does not mean one tonne.
Choose one controlling package basis. If a label gives both volume and mass, use the basis relevant to the order calculation rather than applying two conversions at once. Whole packages round upward; if the supplier sells multiples of six, 22 bag equivalents become 24 bags.
When density is unnecessary
Bulk volume quotes and volume-labeled packages can be planned without mass. Leave density unanswered if it is not known. The tool preserves a valid volume result while showing mass as unavailable.