Free Online Tool

Slab Calculator — Concrete Volume, Rebar & Cost

Calculate concrete slab volume, cubic yards, bags, ready-mix trucks, rebar requirements, wire mesh, and estimated cost for any slab type.

3
Slab Types
2
Reinforcements
2
Systems
100%
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Enter Slab Details

Measurement System
Slab Type
Reinforcement

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Enter your slab dimensions and click Calculate to see estimates.

Frequently Asked Questions

A concrete slab calculator estimates the volume of concrete needed for a slab along with reinforcement requirements. By entering the length, width, and thickness, it calculates cubic yards of concrete, bag quantities, ready-mix trucks, rebar, and wire mesh needed.
On-grade slabs are poured directly on the ground, commonly used for patios, driveways, and garage floors. Suspended slabs are elevated above grade and require additional structural reinforcement and formwork. Reinforced slabs include rebar or wire mesh for added strength.
Multiply length (ft) by width (ft) by thickness (in / 12), then divide by 27 to get cubic yards. For example, a 20ft × 10ft slab at 6 inches thick: 20 × 10 × 0.5 ÷ 27 = 3.7 cubic yards. Add 5–10% for waste and over-excavation.
Rebar is recommended for structural slabs, driveways with heavy loads, suspended slabs, and slabs on expansive soils. For standard residential slabs on grade, wire mesh may be sufficient. Always check local building codes for specific reinforcement requirements.
Wire mesh is typically sold in rolls of 5ft × 150ft (750 sq ft). To estimate, divide your slab area by the roll coverage area and round up. Overlap mesh sheets by at least 6 inches at the seams. This calculator uses a standard roll size of 750 sq ft.
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