Calculate concrete slab square footage, concrete volume, cubic yards, concrete bags, gravel base, rebar, mesh, waste, and project cost from slab length, width, and thickness.
Rectangular slab mode:
The calculator multiplies slab length by slab width to estimate square footage, then multiplies by thickness for volume.
Multiple slabs mode:
The calculator multiplies one slab area by the number of same-size slabs.
Known area mode:
The calculator starts from your known slab area and estimates concrete volume, bags, base material, and cost.
Circular slab mode:
The calculator uses the slab diameter to estimate circular slab area, perimeter, volume, and material quantity.
A concrete slab area calculator helps estimate square footage and concrete volume for patios, garages, driveways, sidewalks, shed slabs, foundation slabs, and flatwork projects.
It can help calculate slab area, concrete cubic feet, concrete cubic yards, concrete bags, gravel base, forms, rebar or mesh length, waste, and estimated project cost.
Your result shows slab square footage, perimeter, concrete volume, cubic yards, cubic yards with waste, concrete bags, gravel base volume, form length, rebar or mesh estimate, and estimated cost.
Multiply slab length by slab width. For example, a 20 foot by 12 foot slab has an area of 240 square feet.
Multiply slab area by slab thickness. Convert thickness to feet first. For example, 4 inches is 0.333 feet.
Divide concrete cubic feet by 27. The calculator also adds your waste percentage so you can estimate cubic yards with extra allowance.
Divide cubic feet with waste by the yield of one concrete bag. Bag yield varies by bag size, so enter the cubic-foot yield listed on the bag.
No. It is an estimate. Actual concrete needs vary by excavation depth, subgrade condition, form accuracy, slope, compaction, waste, reinforcement, and finishing method.