Plan concrete volume, road base, reinforcement, joints, cost, and ordering for a garage floor or workshop.
The starting garage preset is 24 × 24 ft at 4 inches thick with a 4-inch road-base layer, 3500 psi concrete, a rebar grid, and a 7% order allowance. Presets also cover one-car garages, truck and SUV use, workshops, three-car layouts, and a 6-inch heavy-duty slab. The calculator reports concrete volume, bags, ready-mix loads, base, reinforcement, forms, joints, and rough material cost.
A simple rectangular calculation is useful for the field of the slab, but garage foundations may also include thickened edges, grade beams, turned-down walls, footings, pits, drains, or separate equipment pads. Measure those features independently. Vehicle lifts and heavy equipment require manufacturer and engineer specifications; the heavy-duty preset is only a planning starting point.
Consider subgrade preparation, vapor-control requirements, drainage slope, floor finish, door openings, and isolation from walls or columns. In cold regions, garage aprons and exposed edges may have different freeze-thaw and de-icing-salt exposure than the protected interior floor. Confirm concrete mix, air content, reinforcement support, placing sequence, and curing plan before ordering.
At 4 inches thick, the slab field is about 7.11 cubic yards before waste. With a 7% allowance, the planning order is about 7.61 cubic yards, excluding footings or thickened edges.
It can estimate volume for an entered thickness, but lift slabs require the lift manufacturer’s layout and structural requirements. Do not treat the preset as engineered design.