Concrete Calculator
Calculate how much concrete you need for slabs, footings, patios, and driveways. Get estimates in cubic yards, cubic feet, and number of bags.
Results
How to Use This Concrete Calculator
Enter the length, width, and thickness of your project area. Our concrete calculator will estimate the total volume of concrete needed in cubic feet and cubic yards. It also calculates the number of 60lb and 80lb premix bags required for your project.
Tips for Ordering Concrete:
- Order 5-10% extra concrete to account for spillage and uneven subgrades.
- A standard 4-inch slab is suitable for most patios and walkways.
- Driveways should be at least 6 inches thick for proper load-bearing capacity.
- For large projects, ready-mix concrete delivered by truck is more cost-effective than bagged mix.
- Always check your local building codes for minimum thickness requirements.
Frequently Asked Questions
How many 80lb bags of concrete do I need for a 10x10 slab?
For a 10x10 slab at 4 inches thick, you need approximately 1.23 cubic yards of concrete, which equals about 56 bags of 80lb mix or 74 bags of 60lb mix.
How thick should a concrete slab be?
A standard patio or walkway slab should be 4 inches thick. Driveways need at least 6 inches for proper load-bearing. Heavy-use areas like garages may require 8 inches.
Should I order extra concrete?
Yes, always order 5-10% extra concrete to account for spillage, uneven subgrades, and slight variations in depth. It's better to have a little extra than to run short.
What is the difference between 60lb and 80lb concrete bags?
A 60lb bag yields about 0.45 cubic feet of concrete, while an 80lb bag yields about 0.6 cubic feet. For large projects, 80lb bags are more economical and require fewer bags to mix.