Pre-Mixed Bags Needed:
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How to Calculate Concrete Volume
Concrete is sold by the cubic yard (27 cubic feet) for truck delivery, or by the bag for smaller projects.
Slab Formula
Column/Post Formula
Converting to Cubic Yards
Pre-Mixed Concrete Bag Coverage
- 40 lb bag: ~0.30 cubic feet
- 60 lb bag: ~0.45 cubic feet
- 80 lb bag: ~0.60 cubic feet
For projects over 1 cubic yard, consider ordering ready-mix concrete delivered by truck. It's often more cost-effective and ensures consistent quality.
Frequently Asked Questions
How much extra concrete should I order?
Order 10% extra to account for spillage, uneven ground, and slight measurement errors. Need concrete for fence posts? Try our Fence Post Concrete Calculator.
How thick should a concrete slab be?
4" for sidewalks and patios, 5-6" for driveways, 6-8" for heavy vehicles or RV pads. Try our Patio Concrete Calculator or Driveway Concrete Calculator for project-specific estimates.
Can I mix concrete by hand?
For small projects (under 1/3 cubic yard), hand mixing is fine. Larger projects benefit from a mixer or ready-mix delivery.