Find cubic yards or bags of concrete required to pour slabs.
Calculator Parameters
Enter details and click calculate to view the results instantly.
Calculation Examples
Scenario Inputs
Output Result
length : 10, width : 10, thickness : 4
Volume: 1.23 Cubic Yards (~ 56 bags of 80lb)
About Concrete Calculator
Slab Concrete Volume Calculator. Find cubic yards or bags of concrete required to pour slabs. Starlightopia provides this tool completely free and online, optimized for instant, accurate computations.
How It's Calculated
What is the formula to calculate concrete volume for a slab?
Volume in Cubic Feet = Length (ft) x Width (ft) x [Thickness (in) / 12]. Divide the result by 27 to find the volume in cubic yards.
Technical Specifications
CategoryConstruction
Target ValueConcrete Volume Needed
Inputs Required (3)
Slab Length (Feet) (number)
Slab Width (Feet) (number)
Slab Thickness (Inches) (number)
Frequently Asked Questions
What is the formula to calculate concrete volume for a slab?
Volume in Cubic Feet = Length (ft) x Width (ft) x [Thickness (in) / 12]. Divide the result by 27 to find the volume in cubic yards.
How many 80lb bags of mixed concrete are needed to fill one cubic yard?
It takes approximately 45 standard 80lb bags of mixed concrete to fill one cubic yard of volume.
What is a safe waste margin factor to add to a concrete order?
Adding a 5% to 10% waste margin helps cover structural spills, base unevenness, and mistakes during the pour.
How long does fresh concrete take to cure completely?
Concrete reaches about 70% of its full strength within 7 days, and cures completely after 28 days.
What is the standard thickness used for residential concrete driveways?
Residential driveways are typically poured at a thickness of 4 to 6 inches to support standard vehicle weights.