Concrete Calculator
Calculate concrete volume and bags needed for your project.
Dimensions
feet
feet
inches
Concrete Needed
Cubic Yards
1.23
For ready-mix orders
Cubic Feet
33.33
Cubic Meters
0.94
Bags Needed:
80 lb bags: 56
60 lb bags: 75
About This Calculator
The Concrete Calculator helps you determine how much concrete you need for your construction project. Simply enter the dimensions of your slab, footing, or other concrete structure, and the calculator will compute the volume in cubic yards, cubic feet, and cubic meters.
The calculator also estimates the number of concrete bags you'll need based on standard 80-pound and 60-pound bag sizes. This helps you plan your project and order the right amount of concrete.
Formula & Calculation Method
Concrete Volume Calculation:
Volume (Imperial):
Volume (cubic feet) = Length × Width × Depth (feet)
Depth (feet) = Depth (inches) ÷ 12
Volume (cubic yards) = Volume (cubic feet) ÷ 27
Volume (Metric):
Volume (cubic meters) = Length × Width × Depth (meters)
Depth (meters) = Depth (cm) ÷ 100
Bags Needed:
80 lb bags = Cubic Feet ÷ 0.6
60 lb bags = Cubic Feet ÷ 0.45
Standard concrete coverage: An 80-pound bag covers approximately 0.6 cubic feet, while a 60-pound bag covers approximately 0.45 cubic feet. Always order slightly more than calculated to account for waste and variations.
How to Use This Calculator
- Select Unit System: Choose feet/inches or meters/centimeters.
- Enter Length: Input the length of your concrete area.
- Enter Width: Input the width of your concrete area.
- Enter Depth: Input the depth (thickness) of the concrete.
- View Results: See the volume needed and number of bags required.
Frequently Asked Questions
How do I calculate concrete for a slab?
Measure the length and width of the slab in feet, then measure the depth (thickness) in inches. Enter these values into the calculator to get the volume in cubic yards and the number of bags needed.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard. This is the standard unit for ordering ready-mix concrete.
How much concrete does a bag cover?
An 80-pound bag of concrete covers approximately 0.6 cubic feet, while a 60-pound bag covers approximately 0.45 cubic feet. Actual coverage may vary slightly by mix and conditions.
Should I order extra concrete?
Yes, it's recommended to order 5-10% more concrete than calculated to account for waste, spillage, and variations in depth. It's better to have a little extra than to run short.
Expert Reviewed
This calculator was reviewed by NumCalculators Editorial Team, Multi-disciplinary Expert Team