Concrete Calculator
Estimate how much concrete you need for slabs, footings, walls, columns, and stairs. Add multiple pours, include waste, and instantly see volume, bag counts, and estimated cost.
Concrete Sections
Mix slabs, footings, walls, and stairs in one estimate, then total everything together.
Patios, shed pads, driveways, and rectangular pours.
Cubic Yards
0
Cubic Feet
0
Cubic Meters
0
Total Concrete Needed
Includes a 10% waste factor for spillage, over-excavation, and uneven forms.
Total Cubic Yards
0
Total Cubic Feet
0
Total Cubic Meters
0
Ready-Mix Bags Needed
40 lb bags
0
60 lb bags
0
80 lb bags
0
Estimated Material Cost
$0
Based on $0 per cubic yard.
How to Use
- Choose whether your measurements are in feet plus inches or meters.
- Add one or more concrete sections, then pick the shape that matches each pour area.
- Enter the dimensions for every section, such as slab length and thickness or stair rise and run.
- Optional: turn on the 10% waste factor and enter your local price per cubic yard for a quick cost estimate.
- Review the combined totals in cubic yards, cubic feet, cubic meters, and ready-mix bag counts.
Frequently Asked Questions
How much concrete is in a cubic yard?
One cubic yard of concrete equals 27 cubic feet or about 0.7646 cubic meters. Ready-mix suppliers typically sell concrete by the cubic yard.
Should I add extra concrete for waste?
Usually yes. Many contractors add 5% to 10% extra to cover uneven subgrades, spillage, over-excavation, and variation in forms. This calculator includes an optional 10% waste factor.
What is the difference between concrete and cement?
Cement is one ingredient in concrete. Concrete is made from cement, sand, gravel or aggregate, and water. Most people asking for cement volume actually mean concrete volume.
How many bags of concrete do I need?
That depends on the bag size and total volume. As a rule of thumb, an 80 lb bag yields about 0.6 cubic feet, a 60 lb bag yields about 0.45 cubic feet, and a 40 lb bag yields about 0.3 cubic feet.
Is it better to buy bags or order ready-mix?
For small jobs like fence posts or a few footings, bagged concrete is often practical. For larger pours, ready-mix is usually faster, more consistent, and often more cost-effective once you need around a yard or more.