How much does a yard of concrete cover?
One cubic yard covers about 81 square feet at 4 inches thick, 65 square feet at 5 inches, and 54 square feet at 6 inches. Divide 27 by the depth in feet to get the coverage for any other depth.
Coverage by slab depth
How Much Does a Yard of Concrete Cover?
One cubic yard of concrete covers about 81 square feet at 4 inches thick, 65 square feet at 5 inches, and 54 square feet at 6 inches. Thickness is the only thing that changes the answer.
The Short Answer
A cubic yard of concrete contains 27 cubic feet. To find how much area it covers, divide 27 by the pour depth expressed in feet. At 4 inches — the most common depth for patios and walkways — the depth is 4 ÷ 12 = 0.333 feet, so 27 ÷ 0.333 gives about 81 square feet. That is roughly a 9 × 9 ft square, or a 4 ft wide walkway just over 20 feet long.
This is the single most misunderstood number in concrete estimating, because a cubic yard is a volume and square feet measure an area. There is no fixed answer to “how many square feet in a yard of concrete” until you decide how thick the pour will be. The same yard that covers 108 square feet at 3 inches covers only 54 square feet at 6 inches. Depth is doing all the work.
Yard of Concrete Coverage Chart
Every row below uses the same one cubic yard. The only variable is thickness, which is why the coverage falls so sharply as the slab gets deeper.
| Thickness | Coverage per yard | Equivalent square | Coverage with 10% waste |
|---|---|---|---|
| 2 in | 162 sq ft | 12.7 × 12.7 ft | 147 sq ft |
| 3 in | 108 sq ft | 10.4 × 10.4 ft | 98 sq ft |
| 4 in | 81 sq ft | 9.0 × 9.0 ft | 74 sq ft |
| 5 in | 65 sq ft | 8.1 × 8.1 ft | 59 sq ft |
| 6 in | 54 sq ft | 7.3 × 7.3 ft | 49 sq ft |
| 8 in | 41 sq ft | 6.4 × 6.4 ft | 37 sq ft |
| 12 in | 27 sq ft | 5.2 × 5.2 ft | 25 sq ft |
The final column matters more than it looks. Coverage figures describe perfect geometry, but real subgrade is uneven, forms bow slightly, and some material stays in the chute or the wheelbarrow. Planning on 74 square feet per yard at 4 inches rather than the full 81 is what keeps a pour from stopping three feet short of the far form. To go the other direction and turn a known area into an order quantity, the concrete yard calculator does the arithmetic and applies the waste factor for you.
Working Backwards From Your Area
Most projects start from the opposite direction: you know the area and need the yardage. Multiply the square footage by the depth in feet, then divide by 27. A 12 × 14 ft patio is 168 square feet; at 4 inches that is 168 × 0.333 = 56 cubic feet, and 56 ÷ 27 = 2.07 cubic yards. Add 10% and the planning figure is about 2.28 cubic yards, which a supplier would likely round to 2.5.
A quicker mental check for 4-inch work is to divide your square footage by 81. The same 168 square feet gives 168 ÷ 81 = 2.07 yards, matching the long calculation exactly. For 6-inch work, divide by 54 instead. These two divisors cover the large majority of residential flatwork and are worth remembering when you are standing in the yard without a calculator. For the full worked method across other shapes, see how many yards of concrete you need.
Coverage per Bag Instead of per Yard
Small pours are usually planned in bags rather than yards, and the same logic applies with a smaller unit. An 80 lb bag yields about 0.60 cubic feet, so at 4 inches thick it covers roughly 1.8 square feet. A 60 lb bag yields about 0.45 cubic feet and covers about 1.35 square feet at the same depth. A 40 lb bag yields about 0.30 cubic feet and covers about 0.9 square feet.
Those numbers explain why bagged material stops making sense quickly. Covering a 10 × 10 ft pad at 4 inches takes about 62 of the 80 lb bags — well over a ton of material to carry, open, and mix by hand. Product yields also vary between manufacturers, so treat these as planning figures and check the label on what you actually buy. The concrete bag calculator compares all three bag sizes for your dimensions, and how many bags are in a yard covers the yield maths in more detail.
Choosing the Depth That Sets Your Coverage
Because thickness controls coverage, the depth decision controls the budget. Walkways and patios carrying only foot traffic are commonly poured at 4 inches. Garage floors and residential driveways are typically 4 to 6 inches, with 6 preferred where pickups or trailers park. Workshop floors and equipment pads often run 6 inches or more. Moving a 400 square foot slab from 4 inches to 6 inches raises the order from about 4.9 to 7.4 cubic yards — a 50% increase in material for the same footprint.
These are planning conventions rather than engineering advice. Soil conditions, climate, reinforcement, and local building codes all affect the depth a slab actually requires, so confirm anything structural with a professional before ordering. Our guide to how thick a concrete slab should be compares depths by project type, and the concrete slab calculator shows the volume and bag count change as you adjust the thickness.
Frequently Asked Questions
How many square feet are in a cubic yard of concrete?
A cubic yard is a volume, not an area, so it has no fixed square footage. Its coverage depends entirely on how thick you pour it — the same yard covers twice the area at 3 inches as it does at 6 inches.
How much will 1 yard of concrete cover at 4 inches?
About 81 square feet, which is roughly a 9 × 9 ft square. After a 10% waste allowance, plan on covering closer to 73 square feet per yard ordered.
How much area does a 80 lb bag of concrete cover?
An 80 lb bag yields about 0.60 cubic feet, which covers about 1.8 square feet at 4 inches thick. It takes roughly 45 of these bags to equal one cubic yard.
Why does my supplier quote yards instead of square feet?
Concrete is sold by volume because the same surface area can need very different amounts of material depending on thickness. Suppliers quote cubic yards and let you decide the depth.