Concrete Slab Calculators
A slab is volume plus reinforcement plus the thickened edge nobody remembers to price. These run the common sizes end to end, so you can compare a 20x20 patio against a 24x24 garage pad without redoing the arithmetic each time.
There are 7 calculators here: Concrete Slab Cost Calculator (concrete volume, bag count and slab cost), 20x20 Concrete Slab Cost Calculator (concrete, base and cost for a 20 by 20 foot slab), 24x24 Garage Slab Concrete & Cost Calculator (concrete, base and cost for a two-car garage slab), 30x40 Shop Slab Cost Calculator (concrete, base and cost for a 30 by 40 shop slab), and 3 more below.
They all work the same way: quantity first, then a waste allowance you can change, then a price built from verified figures and adjusted for your state. Cost is always a range rather than a single number, and every assumption behind it is printed on the page with its source and the date it was last checked.
In this topic
- Concrete Slab Cost CalculatorConcrete volume, bag count and slab cost.
- 20x20 Concrete Slab Cost CalculatorConcrete, base and cost for a 20 by 20 foot slab.
- 24x24 Garage Slab Concrete & Cost CalculatorConcrete, base and cost for a two-car garage slab.
- 30x40 Shop Slab Cost CalculatorConcrete, base and cost for a 30 by 40 shop slab.
- Slab-on-Grade Foundation Cost CalculatorConcrete, thickened edge and cost for a monolithic slab foundation.
- Concrete Patio Slab Cost CalculatorConcrete, base and cost for a patio slab.
- Rebar Grid & Spacing CalculatorBar count, total footage and cost for a rebar mat.