Concrete Slab Calculator
Estimate concrete volume, bags, and cost for your slab project
Length of the slab
Width of the slab
Standard: 4" for patio, 6" for driveway
Concrete Volume
—
cubic yards
Concrete Volume
—
cubic feet
60 lb Bags
—
bags
80 lb Bags
—
bags
Estimated Cost
—
USD
How to Use This Calculator
Planning a concrete slab project? Whether you are pouring a patio, driveway, shed floor, or foundation, getting the right amount of concrete is crucial. Our calculator helps you estimate exactly how much concrete you need.
- Measure the length and width of your slab area in feet
- Determine the required thickness (4" for patios, 6" for driveways)
- Enter your dimensions in the calculator
- Add 5-10% extra for spillage
- Order ready-mix for projects over 1 cubic yard
AI Insights
Smart analysis for your project
Smart Estimates
Our AI cross-references material costs, regional pricing, and project complexity for more accurate estimates.
Waste Optimization
AI-calculated waste factors based on project type, not flat percentages. Saves 5-15% on material costs.
Best Practices
Recommendations derived from building codes, contractor data, and thousands of completed projects.
Calculation Formula
Volume (cu ft) = Length x Width x (Thickness / 12)
Volume (cu yd) = Volume (cu ft) / 27
Frequently Asked Questions
How many bags of concrete do I need for a 10x10 slab?
For a 10x10 slab at 4 inches thick, you need approximately 56 bags of 80lb concrete or 75 bags of 60lb concrete, about 1.23 cubic yards.
How thick should a concrete slab be?
Standard: 4 inches for patios and walkways, 5-6 inches for driveways, 6-8 inches for heavy loads.
How much does a concrete slab cost?
Average cost is $4-$8 per square foot installed, or $110-$165 per cubic yard for ready-mix. A 10x10 slab typically costs $400-$800.
Should I order ready-mix or use bags?
For projects over 1 cubic yard, ready-mix is usually more cost-effective. For smaller projects, bagged concrete is more practical.