Concrete Volume Calculator
Calculate how many cubic yards or meters of concrete you need for slabs, footings, columns, and other projects.
Concrete Needed
Concrete volume is calculated using simple geometry based on the shape of your project.
For rectangular slabs and footings:
Volume = Length × Width × Thickness
Common concrete thicknesses:
- Sidewalks: 4 inches (10 cm)
- Driveways: 4–6 inches (10–15 cm)
- Garage slabs: 4–6 inches (10–15 cm)
- Footings: 8–12 inches (20–30 cm)
- Foundation walls: 8–10 inches (20–25 cm)
Ordering concrete:
- Ready-mix concrete is sold by the cubic yard (US) or cubic meter (metric).
- One cubic yard = 27 cubic feet.
- One cubic meter = 35.31 cubic feet.
- Always order 5–10% extra to account for uneven ground, spillage, and slight over-excavation.
Pre-mixed bags:
- A standard 80 lb bag yields about 0.6 cubic feet.
- You need about 45 bags per cubic yard.