Example Tool
Concrete Mixing product recommendation placeholder
Concrete Calculator
Calculate how much concrete you need for slabs, floors and other building projects.
- Free
- No signup
- Metric & Imperial
Concrete estimate
Ready when you are
Enter your project dimensions and select Calculate to see volume, weight, bag quantities and your recommended order.
Quick Answer
The calculator multiplies length × width × thickness to determine concrete volume, then converts the result into cubic yards, cubic feet and cubic meters. Your chosen waste allowance is applied separately to the recommended order.
How to Use This Calculator
- 1Enter the measured length.
- 2Enter the measured width.
- 3Enter the slab thickness and select units.
- 4Choose a waste allowance.
- 5Select Calculate to review your estimate.
How the Calculation Works
For a rectangular slab, use Volume = Length × Width × Depth. The calculator normalizes every measurement before multiplying, so you can mix feet, inches, meters and centimeters.
10 ft × 6 ft × (4 in ÷ 12) ≈ 20 ft³
20 ft³ ÷ 27 ≈ 0.74 yd³
Material Planning
| Project | Typical depth | Planning note |
|---|---|---|
| Walkway | 4 in | Confirm local requirements and base preparation. |
| Patio slab | 4 in | Consider slope, reinforcement and joint layout. |
| Driveway | 4–6 in | Vehicle loads may require extra thickness. |
Tips Before Ordering
- Measure more than once and use the finished dimensions.
- Account for uneven excavation and spillage with a suitable waste factor.
- Ask your supplier about minimum loads, delivery access and mix specifications.
- Concrete requirements vary by project and location; check applicable codes.
Disclaimer: BuildCalcWorks provides planning estimates only. Actual material requirements can vary because of site conditions, excavation, formwork, compaction, product yield and measurement accuracy. Verify quantities and project requirements before ordering materials or starting construction. Read full Disclaimer.
Related Calculators
Frequently Asked Questions
Tools & Materials for Your Project
Helpful products and materials related to this calculation.
Disclosure: BuildCalcWorks may earn a commission from qualifying purchases made through links on this page, at no additional cost to you.
Example Tool
Concrete Finishing product recommendation placeholder
Example Tool
Measuring Tools product recommendation placeholder
Example Tool
Concrete Forms product recommendation placeholder
Example Tool
Safety Equipment product recommendation placeholder
Related Guides
Flooring
How to Calculate Square Footage for Flooring
Learn how to calculate square footage for flooring, measure rooms correctly, account for irregular areas and add waste before ordering flooring materials.
Read guideFlooring
How Much Extra Flooring Should You Buy?
Learn how much extra flooring to buy for cuts and waste, when to use 5%, 10% or 15%, and how to calculate boxes for your flooring project.
Read guide