🧮 Concrete Slab Calculator
Professional concrete volume calculator that converts length × width × depth measurements into cubic yards. Features multiple unit inputs (feet, inches, meters), cost estimation, delivery planning, and educational calculation breakdowns for construction projects.
Concrete Volume Results:
20ft × 10ft × 4in = 2.47 Cubic Yards
Including 10% waste factor: 2.72 cubic yards
📐 Dimension Breakdown
🔢 Calculation Steps
How to Use This Concrete Slab Calculator
This concrete slab calculator helps you determine the exact volume of concrete needed for your project in cubic yards. Simply enter your slab dimensions and let the calculator handle all unit conversions and volume calculations.
- Enter Dimensions: Input the length, width, and depth/thickness of your concrete slab using your preferred units.
- Select Units: Choose from feet, inches, meters, or centimeters for consistent measurements across all dimensions.
- Configure Options: Enable waste factor calculation (recommended) and cost estimation if needed.
- Calculate Volume: Click "Calculate Concrete Volume" to get instant results in cubic yards with detailed breakdowns.
- Review Results: View the cubic yards needed, step-by-step calculations, and cost estimates if enabled.
The calculator automatically converts between units and provides professional-grade results suitable for ordering concrete from ready-mix suppliers.
How It Works
The concrete volume calculation follows standard construction industry formulas with precise unit conversions:
- Volume Calculation: Multiplies length × width × depth to get cubic volume in the input units
- Unit Conversion: Converts the result to feet, then divides by 27 to get cubic yards (since 1 cubic yard = 27 cubic feet)
- Waste Factor: Adds 10% to account for typical concrete loss during mixing, transport, and placement
- Cost Estimation: Multiplies total cubic yards by your local concrete price for budget planning
All calculations use precise conversion factors: 1 yard = 3 feet, 1 foot = 12 inches, 1 meter = 3.28084 feet, 1 centimeter = 0.0328084 feet. The tool ensures accurate results regardless of your input unit preference.
When You Might Need This
- • Calculate concrete needed for a backyard patio slab project
- • Estimate cubic yards for a garage floor concrete pour
- • Plan concrete requirements for a basement floor renovation
- • Determine volume for a shed foundation concrete slab
- • Calculate concrete for a driveway extension project
- • Estimate material needs for a workshop floor concrete pour
- • Plan concrete requirements for a deck foundation slab
- • Calculate volume for a sidewalk or walkway concrete project
- • Estimate concrete needs for a commercial building floor slab
- • Determine cubic yards for a pool deck concrete installation
Frequently Asked Questions
How do I convert inches to feet for the depth measurement?
To convert inches to feet, divide by 12. For example, 4 inches = 4 ÷ 12 = 0.333 feet. Our calculator handles this conversion automatically when you select your input units, so you can enter measurements in any unit and get accurate cubic yard results.
Why should I include a waste factor in my concrete calculation?
A 10% waste factor accounts for normal concrete loss due to spillage, over-excavation, uneven sub-grade, and material handling. Professional contractors always order 5-15% extra concrete to ensure they have enough material to complete the project without delays or additional delivery charges.
How many cubic yards of concrete do I need for a standard 10x10 patio?
For a 10ft × 10ft patio with standard 4-inch thickness: Volume = 10 × 10 × 0.333 = 33.33 cubic feet ÷ 27 = 1.23 cubic yards. With a 10% waste factor, order approximately 1.4 cubic yards of concrete.
Can this calculator handle different units for length, width, and depth?
Currently, all three dimensions (length, width, depth) must use the same unit selected in the input unit dropdown. You can choose from feet, inches, meters, or centimeters. For mixed units, convert all measurements to the same unit before calculating.
What's the difference between cubic feet and cubic yards for concrete orders?
Concrete is typically ordered in cubic yards because it's the industry standard. One cubic yard equals 27 cubic feet (3ft × 3ft × 3ft = 27 ft³). Ready-mix concrete trucks are sized in cubic yard capacities, usually ranging from 6 to 12 cubic yards per load.