Concrete Slab Volume Calculator
Planning a concrete slab project.
Rebar Calculator
Estimate how much steel rebar you need for any concrete project. Rebar (steel reinforcement) gives concrete its tensile strength — without it, concrete cracks under tension and pulls apart. Our calculator uses a reinforcement ratio (rebar volume ÷ total concrete volume) to compute total rebar weight and the number of common bar lengths (20 ft).
Formula
Rebar Weight = Concrete Volume × Rebar Ratio × Steel Density (490 lb/cu ft)
FAQ
What is a typical rebar ratio?
Residential slabs typically use 0.5-1.5% rebar by volume. Driveways may need 1-2%, while commercial structures go up to 2-4%. Always follow local building codes.
How much does rebar cost?
As of 2024, steel rebar is roughly $0.80-$1.20 per pound depending on size and location. Our calculator gives you the total weight — multiply by current price per lb.
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