Concrete Slab Calculator

🧱
Concrete Slab + Pad + Cylinder Calculation
Calculate volume, weight & materials for Slab, Pad & Cylinder shapes
Units & Grade
Select Shape
Dimensions
ft
ft
ft
Wastage Buffer
Accounts for spillage, overpouring & formwork loss 7%
⚠️ Please enter valid positive values in all required fields.
βœ… Calculation complete for Slab β€” M20
Net Volume
β€”
mΒ³
Order Volume (incl. wastage)
β€”
mΒ³
Approx. Weight
β€”
tonnes
Premix Bags (50 kg)
β€”
Γ— 50 kg bags
MaterialMix RatioQuantity Required

Concrete Slab Installation Cost Calculator

The most used tool on this page. This is the main branch of ourΒ concrete calculator. Enter your length, width, and slab thickness and get cubic yards, cubic feet, bag count, and total cost instantly. This works as a full slab cost calculator when you enter your local ready mix price.Β 

Best for patios, driveways, garage floors, sidewalks, and basement slabs.

Concrete Pad Calculator

Built for square and rectangular pads. Includes a pad thickness calculation so you can match depth to your load type.Β 

Best for AC unit pads, equipment bases, column footings, and fence posts.

Concrete Calculator Cylinder

Handles round shapes using the formula Ο€ Γ— rΒ² Γ— h. Works as a column extreme cylinder concrete calculation for any circular pour.Β 

Best for deck piers, sonotube forms, round columns, and post holes.

How Thick Should a Concrete Slab Be?

Slab thickness depends on the load it carries. For most residential projects in the USA, 4 inches is the standard and code-compliant depth. Driveways and garage floors typically need 4 to 6 inches. Sheds and patios do fine at 4 inches. Heavy equipment or vehicle storage calls for 6 inches minimum with added rebar or wire mesh. Always check your local building codes because thickness requirements vary by state and county.

Frequently Asked Questions

How much concrete do I need for a 12Γ—12 slab?

At 4 inches thick, a 12Γ—12 slab needs 1.78 cubic yards. At 6 inches thick, that rises to 2.67 cubic yards. Always round up and add 10% for waste.

Β You’ll need 1.23 cubic yards that is roughly 10 bags of 80 lb mix. For pours under 1 cubic yard, bags are usually cheaper than ordering a truck.

At 4 inches thick: 14.81 cubic yards. At 6 inches: 22.22 cubic yards. This size requires a ready-mix delivery. Use our slab calculator to get the exact volume before you call your supplier.

Material cost typically runs $600–$1,200 depending on your region and mix. Full installed cost that includes labor plus materials ranges from $1,600–$3,200 in the USA. Use our concrete slab installation cost calculator and enter your local per-yard rate for a real number.

Materials run roughly $200–$500. With professional installation in the USA, expect $600–$1,200 total. Costs run higher in the Northeast and West Coast compared to the South and Midwest.

Installed cost averages $400–$900 depending on thickness, site prep, and local labor rates. Enter your dimensions in our concrete slab cost calculator above for a location-specific estimate.

Material cost for a 4-inch slab runs $1,200–$2,000. Full installation in the USA averages $3,500–$6,500. Rebar, site grading, and formwork are the biggest cost variables.

You’ll need about 5 bags of 80 lb mix. Buy 6 and the extra bag costs far less than a second trip to the store.

For pours under 1 cubic yard, DIY with bagged mix. For larger slabs, order ready-mix concrete because its per-yard price is lower, and labor costs less than wasted bags. Always calculate your volume first using our concrete estimator to avoid over-ordering.

4 inches is standard for a residential shed floor. If you’re storing heavy equipment or vehicles inside, go 6 inches and add wire mesh or rebar for added strength.

Β At 4 inches thick, a 10Γ—10 slab holds 1.23 cubic yards or 33.3 cubic feet. Enter those dimensions in our slab calculator concrete tool and get the full breakdown instantly.

More Concrete Calculators

Scroll to Top