Volume times density, so the material decides the weight
A cubic foot is a fixed box of space; how much it weighs depends entirely on what fills it. Look up the material\'s density and multiply. 200 ft³ of concrete at 150 lb/ft³ is 30,000 lb — 15 US tons. Water is the reference point at 62.4 lb/ft³.
The same cubic foot, wildly different weight
This is the whole point of needing density. One cubic foot ranges from a couple of pounds of foam to well over a hundred of stone.
Identical volume, top to bottom. Granite is nearly five times a cubic foot of pine, which is why the material choice matters more than the volume.
Density of common materials
| Material | Density (lb/ft³) | 1 cubic yard (27 ft³) |
|---|---|---|
| Water | 62.4 | 1,685 lb |
| Topsoil / dry sand | 100 | 2,700 lb |
| Gravel | 105 | 2,835 lb |
| Asphalt | 145 | 3,915 lb |
| Concrete | 150 | 4,050 lb |
| Granite | 168 | 4,536 lb |
| Pine (softwood) | 35 | 945 lb |
Moisture adds weight: dry sand near 100 lb/ft³ climbs to 120–130 when wet, and loose soil compacts heavier. Divide pounds by 2,000 for US short tons.
Common questions
How do I convert cubic feet to pounds?
Multiply the volume in cubic feet by the material's density in pounds per cubic foot. For example, 10 cubic feet of concrete at 150 lb per cubic foot weighs 1,500 lb. You always need the material, because volume alone does not set weight.
How much does a cubic foot of water weigh?
About 62.4 lb. Water is the usual baseline: concrete is a bit over twice as heavy per cubic foot, while a cubic foot of dry sand is about 100 lb.
How much does a cubic yard weigh?
A cubic yard is 27 cubic feet, so multiply the per-cubic-foot weight by 27. A yard of concrete is about 4,050 lb, and a yard of gravel is roughly 2,835 lb. Mixing up cubic feet and cubic yards is the most common error here.
