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How much concrete do I need for a 12x12 patio?

By the YardBrick Editorial Team · Last updated October 5, 2026

A 12x12 patio at 4 inches thick needs 1.96 cubic yards of concrete with 10% waste, or 89 bags of 80 lb mix.

Check it with your own numbers

Open the Concrete Calculator with these values

Length	12 ft
Width	12 ft
Thickness	4 in
Extra for waste	10 %
Concrete needed	1.96 yd³
Cubic feet	52.8 ft³
80 lb bags	89
60 lb bags	118

The numbers for 144 square feet

12 × 12 × 0.333 ft gives 48 cubic feet, or 1.78 yd³. With 10% added, you need 1.96 yd³ (52.8 ft³). In bags that is 89 of the 80 lb size or 118 of the 60 lb size. Order 2 yards from a ready-mix plant and you will have a small cushion.

Bags are a stretch here

Eighty-nine bags is over 7,000 lb of material to lift twice: once off the pallet and once into the mixer. For a patio this size, a truck or a mini-mix trailer from a local supplier is the sane choice. Some yards rent trailers that hold 1 yard each, so two trips covers it.

Patio-specific details

Slope

Pitch the patio 1/8 to 1/4 inch per foot away from the house. Over 12 ft that is 1.5 to 3 inches of fall. Set the form boards to that slope before you calculate, because sloping the gravel base under a flat-topped form changes the thickness and the yardage.

Control joints

Concrete cracks; joints decide where. On a 4-inch slab, keep panels no bigger than 8 to 10 ft square. For 12x12, one joint each way at 6 ft gives four 6x6 panels that look tidy and crack where you want.

Finish

Broom finish for grip near pools and steps
Exposed aggregate if you want texture without stamping costs
Stamped concrete usually adds a 5th inch of thickness at the contractor's request, which pushes the order to about 2.4 yd³

Before the truck shows up

Make sure the chute can reach. A standard truck chute reaches about 15 to 20 ft past the rear wheels. If the patio is behind the house, book a pump or line up two wheelbarrows and two strong backs.