🧱 Concrete Calculator
Calculate concrete volume needed for your project
How Concrete Calculation Works
Formula
Volume = Length × Width × Depth
- 1Enter the dimensions of your concrete project (length, width, depth).
- 2Select the shape: slab, column, footing, or custom.
- 3The calculator computes the volume in cubic feet.
- 4Volume is converted to cubic yards (divide by 27) for ordering.
- 5The number of pre-mixed bags needed is also estimated.
About Concrete Calculator
Calculate how much concrete you need in cubic yards, cubic feet, or bags. Enter slab, column, or footing dimensions. Estimate cost and materials for your project.
Frequently Asked Questions
How many bags of concrete do I need?
An 80-lb bag makes about 0.6 cubic feet. Divide your total cubic feet by 0.6. For example, 30 cubic feet needs about 50 bags of 80-lb concrete mix.
How thick should a concrete slab be?
Standard residential slabs are 4 inches thick. Driveways should be 5-6 inches. Garage floors and heavy-load areas should be 6 inches or more with reinforcement.
Should I order extra concrete?
Yes, order 5-10% more than calculated to account for spillage, uneven ground, and form irregularities. Running short mid-pour creates weak joints.