🧱 Concrete Calculator
How many bags or yards do you need?
Concrete Buying Guide
Concrete is sold two ways: by the cubic yard from a ready-mix truck ($130-160/yard including delivery) or in bags from home improvement stores. An 80-lb bag makes 0.6 cubic feet; a 60-lb bag makes 0.45 cubic feet. For projects under 1 cubic yard, bags are often more practical. Over 1 yard, a ready-mix truck saves hours of mixing and is usually cheaper per yard.
Always order 10% more than calculated to account for uneven subgrade, spillage, and waste. For slabs, 4 inches is the minimum thickness for foot traffic and light vehicles. Driveways need 5-6 inches. Footings for fences and decks are typically 12 inches wide by 8-12 inches deep, extending below the frost line in cold climates.
Do I need rebar or wire mesh?
For slabs over 4 inches thick or any slab that will bear vehicle weight, use #4 rebar on 18-inch centers or 6x6 welded wire mesh. For footings, use two runs of #4 rebar. For decorative patios with no vehicle traffic, wire mesh alone is sufficient. Rebar adds $0.50-1.00 per square foot to the project cost but dramatically reduces cracking.