Shed: Concrete Calculator Guide
Plan your shed pad in build order — base, concrete and cost, sized to your shed footprint.
A shed pad is the friendliest slab to pour yourself — small enough for bags or a single small ready-mix load. Set your shed size and follow the steps to size the base, concrete and cost. Rebar is optional for a light shed.
Your shed size
This shed needs
1.63 yd³
≈ $660 – $1,440 installed
- 1
Measure & mark the area
Set your width and length above. Square off the corners and mark the perimeter. Not a simple rectangle? Work out the area with the square footage calculator first.
Square footage calculator - 2
Excavate & lay the gravel base
Dig down for the slab plus about 4" of base, then lay and compact crushed gravel so the slab drains and won't heave. This is the volume of base to order.
Gravel base calculator - 3
Pour, screed & finish the concrete
Order or mix the concrete, pour into the forms, screed level, then float and finish. This is the concrete volume and bag count, with 10% waste built in.
Concrete slab calculator - 4
Budget the total cost
See what the finished slab costs — materials if you DIY, or fully installed by a contractor — for your exact size.
Shed base cost
Typical shed sizes & cost
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: