Concrete Yard Calculator
Concrete is sold by the cubic yard, not the square foot. Enter your slab, footing or driveway dimensions and get the cubic yards to order, the bag count if you're mixing by hand, and a rough delivery cost — in one pass.
Every job needs a different calculator
Yardage is the starting point. Once you know the shape of the pour, jump to the calculator built for that job — cost per yard, bag counts, footings, or round forms.
Slab Calculator
Square footage, volume and bag count for patios, sheds and floors.
Open tool →Slab Cost Calculator
Turn a yardage figure into a delivered, finished price estimate.
Open tool →Bags Calculator
How many 40 lb, 60 lb or 80 lb bags for a given volume.
Open tool →Patio Calculator
Materials and cost for a poured patio slab, finishing included.
Open tool →Footing Calculator
Strip footings and foundation walls, by run length and section.
Open tool →Cylinder / Pier Calculator
Round footings, sonotubes, columns and posts by diameter and height.
Open tool →How the yardage formula works
Every calculator on this site reduces to the same core formula. Cubic yards are cubic feet divided by 27, and cubic feet are length × width × depth, all measured in feet.
thickness_ft = thickness_in / 12
// 2. volume in cubic feet
cu_ft = length_ft × width_ft × thickness_ft
// 3. convert to the unit concrete is sold in
cu_yd = cu_ft / 27
// 4. add a waste buffer for spillage & sub-grade dips
order_yd = cu_yd × 1.10
For circles, swap step 2 for the area of a circle: π × (diameter / 2)² × thickness_ft.
Coverage per yard
Common yardage questions
How many feet are in a yard of concrete?
A "yard" of concrete is a cubic yard — 3 ft × 3 ft × 3 ft, or 27 cubic feet of material. It's a volume, not a length, which is why the yard calculator asks for length, width and thickness rather than a single dimension.
How much does a yard of concrete cover?
Coverage depends entirely on thickness. One cubic yard covers about 81 sq ft at a 4" slab thickness, roughly 65 sq ft at 5", and about 54 sq ft at 6". Thicker footings and driveways use noticeably more material per square foot.
How much does 4 yards of concrete cover?
At a standard 4" thickness, 4 cubic yards covers roughly 324 sq ft — enough for a typical single-car driveway apron or a mid-size patio. Use the calculator above with your own thickness for an exact figure.
How big of an area is 4 yards of concrete?
Four cubic yards is 108 cubic feet total. Spread over a 4" slab that's about an 18 ft × 18 ft square; spread over a 6" driveway it shrinks to roughly a 14.7 ft × 14.7 ft square.
How do I figure yards of concrete by hand?
Multiply length × width × thickness in feet to get cubic feet, then divide by 27 to get cubic yards. Round up to the nearest quarter yard, and add 5–10% for waste, spillage and an uneven sub-grade before you place the order.