Construction
Concrete Calculator: How Much Concrete Do You Need?
Learn how to calculate concrete volume for slabs, footings, and columns. Avoid over-ordering and wasted materials.
Ordering the right amount of concrete saves money and prevents project delays. Our calculator handles slabs, footings, columns, and more.
How to Calculate Concrete Volume
Volume = Length × Width × Depth (for slabs). For cylinders (columns): Volume = π × radius² × height. Always add 5-10% extra for waste and settling.
Common Concrete Projects
- Driveway: Typically 4 inches thick, wider at edges for support
- Patio: 4 inches thick for foot traffic, 6 inches for hot tubs
- Footings: Below frost line, typically 12-24 inches wide
- Columns: Reinforced with rebar, volume calculated as cylinders
Concrete Ordering Tips
Ready-mix concrete is sold by cubic yard. One cubic yard covers about 81 square feet at 4 inches thick. Small projects may use bagged concrete (80 lb bags make about 0.6 cubic feet each).
Cost Factors
Concrete costs $125-150 per cubic yard for materials. Delivery fees, pump truck rental, and reinforcement (rebar/wire mesh) add to total cost.
Frequently Asked Questions
How much concrete do I need for a 10x10 slab?
A 10×10 foot slab at 4 inches thick requires about 1.23 cubic yards. Always order 10% extra (1.35 yards) for waste.
What is the difference between concrete and cement?
Cement is an ingredient in concrete. Concrete = cement + water + aggregate (sand, gravel). Cement is the binder; concrete is the final product.
How thick should a concrete slab be?
Standard slabs: 4 inches. Driveways: 4-6 inches. Garage floors: 6 inches. Heavy equipment: 8+ inches with reinforcement.