Short answer: a 10×10 slab poured at the standard 4-inch thickness needs 1.24 cubic yards of concrete. Add the usual 10% safety margin and you should order 1.5 yards of ready-mix — or, if you are mixing it yourself, about 62 bags of 80 lb mix (82 bags of 60 lb).
Concrete needed by slab thickness
| Thickness | Concrete needed (before safety margin) |
|---|---|
| 2 inches | 0.62 cubic yards — 28 × 80 lb bags (38 × 60 lb) |
| 4 inches (standard) | 1.24 cubic yards — 56 × 80 lb bags (75 × 60 lb) |
| 6 inches | 1.85 cubic yards — 84 × 80 lb bags (112 × 60 lb) |
Thickness matters more than most people expect: going from 4 to 6 inches adds 50% more concrete. Patios, walkways and shed bases are fine at 4 inches; driveways and anything vehicles use should be 5–6 inches.
Ready-mix truck or bags?
Under about 1 cubic yard, bags are cheaper and let you work at your own pace. A 10×10 slab sits right at the tipping point: 62 bags is a serious workout with a rented mixer, while a ready-mix truck pours it in minutes — but watch for minimum-order and short-load fees on small loads, and have your forms and help ready before the truck arrives.
Never order the exact amount
Ground is never perfectly level, forms bulge, and some concrete always stays in the wheelbarrow. Pros order 5–10% extra; running short mid-pour leaves a weak cold joint in the slab. The small overage is cheap insurance.
Pouring a different size? Get exact yards and bag counts for your slab in our concrete calculator.