Concrete Calculator
Calculate how many cubic yards or cubic meters of concrete you need for slabs, footings, walls, and columns.
How to Calculate Concrete Volume
Calculate the volume in cubic feet, then convert to cubic yards by dividing by 27 (since 1 cubic yard = 27 cubic feet).
Slab: 20 ft × 10 ft × 0.5 ft (6 inches deep)
Volume = 20 × 10 × 0.5 = 100 cubic feet
Cubic yards = 100 ÷ 27 = 3.70 cubic yards
Tips for Ordering Concrete
Always order 5–10% more concrete than calculated to account for spillage, uneven ground, and form irregularities. Concrete is sold in whole cubic yard increments by most suppliers.
Common Slab Thicknesses
4 inches (0.33 ft): Standard sidewalks and patios. 6 inches (0.5 ft): Driveways and garage floors. 8+ inches (0.67+ ft): Foundations and heavy-load areas.
FAQ
How many bags of concrete make a cubic yard?
Approximately 45 bags of 80-lb concrete mix or 60 bags of 60-lb mix make one cubic yard.
Should I add extra for waste?
Yes, add 5–10% extra to your calculated volume to account for spillage, sub-grade irregularities, and slightly oversized forms.
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Last updated: 2026-08-08