Weight of a volume of material
Approximate mass of a volume of water, aggregate, timber, metal or other materials, from its typical bulk density.
How it is calculated
Mass = volume × the material's bulk density. Bulk density is that of a real pile, including the air gaps between particles; it is the one that matters for hauling, and it is lower than the density of the solid material with no gaps (for example, a single sand grain is denser than a pile of sand).
Typical bulk densities used here (kg/m³, reference values that vary with moisture, compaction and origin): water 1000; dry sand 1500 (1400-1650); wet sand 1800 (1600-2000); gravel 1500 (1350-1650); loose topsoil 1300 (1100-1600); clay 1700 (1600-2100); hardened concrete 2400; solid brick (bulk) 1800; granite stone 2700; limestone 2500 (2300-2700); dry pine wood 500 (450-550); dry oak wood 750 (700-900); iron/steel 7850; copper 8960; aluminium 2700; lead 11340; bulk wheat 780 (720-800); packed or trodden snow 500 (400-600, highly variable).
A typical builder's wheelbarrow has a heaped load capacity of about 60 litres (0.06 m³); the number of wheelbarrows is the volume divided by 0.06, rounded up, and does not depend on density (it is a volume limit, not a weight one: for very dense materials such as gravel or metal, weight can be the real limit before volume is).
Example: 0.5 m³ of iron/steel. Mass = 0.5 × 7850 = 3925 kg = 3.925 t. Wheelbarrows = 0.5/0.06 = 8.33 → 9 (though in practice that load would far exceed what a person can push; metal is moved piece by piece, not by the wheelbarrow-load).
Keep in mind
- These are typical reference values, not those of a specific material: the actual density can vary quite a bit with moisture, degree of compaction, variety (for example, between types of wood or stone) and impurities. For work that depends on the exact weight (for example, the maximum load on a floor slab or a vehicle), weigh a sample if you can.
- The load limit of a wheelbarrow or vehicle is usually a weight limit, not a volume one: check the kilograms too, especially with gravel, stone or metal.
- These figures do not replace a structural calculation: do not use them to size elements that have to bear that weight (floor slabs, beams, footings).