Slab width × length × thickness
Column π × (diameter ÷ 2)² × height × how many
Steps Σ rise × depth × width, stacked
1 cubic yard = 27 cubic feet = 0.7646 m³
| Job | Typical thickness |
|---|---|
| Footpath | 4 in / 100 mm |
| Patio | 4 in / 100 mm |
| Driveway, cars | 4–6 in / 100–150 mm |
| Driveway, heavy vehicles | 6–8 in / 150–200 mm |
| Garage / shed base | 4–6 in / 100–150 mm |
- Order 5-10% over the geometric figure. Subgrade is never perfectly level and some is always lost.
- Bags are only economical below roughly 1 cubic yard. Past that, ready-mix is cheaper and far less work.
- An 80 lb bag yields about 0.6 cubic feet, so a cubic yard takes about 45 of them.
- Concrete weighs roughly 4,000 lb (1,800 kg) per cubic yard — check what the ground and your vehicle can take.