Concrete Slab Calculator
Everything for a slab in one place — concrete, base gravel, rebar and cost, sized for your dimensions.
Concrete slab calculator
Waste & region
Order extra for spillage & uneven subgrade. 10% is typical.
Concrete needed (10% waste in)
7.82 yd³
7.11 yd³ of concrete + waste · 576 sq ft
Bags of concrete needed (rounded up)
352
80 lb
470
60 lb
564
50 lb
704
40 lb
- Ready-mix (delivered)
- $1,038 – $1,661
- Bagged mix (80 lb, DIY)
- $1,936 – $3,168
- Installed by a pro
- $3,168 – $6,912
Estimate only — not a quote. Bag counts are rounded up and include a 10% waste allowance.
You'll also need
Sized for this exact slab — tap any item to open its calculator with your measurements already filled in.
Sizing a concrete slab
A slab pour is more than the concrete: you need a compacted gravel base to drain and support it, rebar or mesh to control cracking, and often a thin sand leveling layer. The calculator sizes all of these from the same width and length, and every "You'll also need" card opens its own calculator with your numbers already in.
Volumes use standard bag yields and a 10% waste allowance; costs are national US averages that vary by region, mix and finish. See our methodology for exactly how each figure is worked out, or check the reference sources: