How Much Does a Yard of Concrete Cover?

Order two yards short on pour day and you are looking at a cold joint, a second delivery fee, and a slab that never quite matches. Knowing how much does a yard of concrete cover is the difference between a clean single pour and an expensive scramble. The short answer: one cubic yard covers 81 square feet at 4 inches thick, 54 square feet at 6 inches, and 108 square feet at 3 inches. The longer answer involves subgrade variation, waste factors, and a little arithmetic that takes about five minutes to get right.

The Basic Math Behind a Cubic Yard

A cubic yard is a volume measurement: 3 feet by 3 feet by 3 feet, or 27 cubic feet. Because concrete is ordered by volume but slabs are planned by area, you have to convert. Divide 27 cubic feet by your slab thickness expressed in feet, and you get the square footage one yard will cover.

At 4 inches — the standard residential slab and sidewalk thickness — that works out to 27 divided by 0.333, which is 81 square feet. Thicken the slab and coverage drops fast. A 6-inch driveway slab built to handle trucks gets only 54 square feet per yard. An 8-inch footing or equipment pad gets 40 square feet. Going thinner stretches coverage: a 2-inch topping pour covers about 162 square feet per yard, though anything under 3.5 inches is fragile for structural use.

Coverage by Slab Thickness

Keep these numbers handy when you sketch out a project. Each figure is coverage per single cubic yard with zero waste:

• 2 inches: 162 sq ft (toppings, overlays only)
• 3 inches: 108 sq ft (mower pads, light-duty walkways)
• 4 inches: 81 sq ft (patios, sidewalks, garage floors, shed slabs)
• 5 inches: 65 sq ft (heavier residential driveways)
• 6 inches: 54 sq ft (driveways with truck traffic, RV pads)
• 8 inches: 40 sq ft (footings, commercial approaches)
• 12 inches: 27 sq ft (pier caps, thick foundations)

Notice the pattern: double the thickness, halve the coverage. That relationship makes quick mental checks easy on site. If your finisher says a 720-square-foot garage floor at 4 inches needs nine yards, you can verify it in your head — 720 divided by 81 is 8.9. He is right.

How to Calculate What Your Project Needs

Work the formula in this order. First, measure length and width in feet and multiply for square footage. Second, convert thickness to feet — 4 inches is 0.33, 5 inches is 0.42, 6 inches is 0.5. Third, multiply area by thickness to get cubic feet, then divide by 27 for cubic yards.

Example: a 12 x 20 foot patio at 4 inches. That is 240 square feet times 0.33 feet, which gives 79.2 cubic feet. Divide by 27 and you need 2.93 yards. Round up and order 3.25 to 3.5 yards once you add waste, which we will get to next.

Odd Shapes and Curves

Break L-shaped pours into rectangles and add them together. For circles, use pi times the radius squared — a 10-foot-diameter fire pit pad is 3.14 times 25, or 78.5 square feet, almost exactly one yard at 4 inches. For free-form curved patios, sketch the shape over a grid of 1-foot squares and count them; it is faster than fighting geometry and accurate within a couple of percent.

Why You Should Always Order Extra

Textbook coverage assumes a perfectly flat, perfectly compacted subgrade. Real subgrades are not. A gravel base that dips a half inch across the slab quietly eats 10 percent of your concrete. Spillage during placement, concrete left in the chute, and forms that bow outward all take their share too.

Seasoned contractors add 5 to 10 percent for slabs on a well-prepped base and 10 to 15 percent for pours over rough or hand-graded soil. On a 3-yard patio, that means ordering 3.25 to 3.5 yards. Ready-mix plants sell in quarter-yard increments, so round up to the next quarter. Running short is far more expensive than a little extra: a second truck trip typically carries a $75 to $200 short-load fee plus a new minimum, and the cold joint between pours becomes a permanent crack line.

What a Yard of Concrete Costs

As of 2026, ready-mix runs $125 to $180 per yard delivered for a standard 3,000 to 4,000 PSI mix, with most of the country landing around $150. Expect add-ons: short-load fees of $50 to $100 per yard under a 5- or 6-yard minimum, fuel surcharges of $20 to $60 per trip, and $10 to $20 per yard for fiber reinforcement or accelerators in cold weather.

That pricing makes small pours disproportionately expensive. A single-yard sidewalk repair might cost $250 to $300 delivered once fees stack up. For anything under about 1.5 yards, compare bagged concrete: an 80-pound bag of Quikrete yields 0.6 cubic feet, so a full yard takes 45 bags. At $5.50 to $7 a bag you will spend $250 to $315 and mix all of it yourself — roughly break-even on cost, but hard labor. Above 2 yards, ready-mix wins every time on both price and quality consistency.

Common Projects and How Many Yards They Take

Real-world benchmarks help you sanity-check your math before calling the plant:

• 10 x 10 shed slab, 4 in: 100 sq ft = 1.25 yards ordered
• 12 x 24 single-car driveway, 5 in: 288 sq ft = 4.5 yards
• 20 x 24 two-car garage floor, 4 in: 480 sq ft = 6.5 yards
• 16 x 20 patio, 4 in: 320 sq ft = 4.25 yards
• 4 x 50 sidewalk, 4 in: 200 sq ft = 2.75 yards
• 24 x 40 pole barn floor, 6 in: 960 sq ft = 19 to 20 yards, poured in sections

Anything over 10 yards usually means multiple trucks, since a standard mixer carries 8 to 10 yards. Schedule them 30 to 45 minutes apart so your crew can strike off one load before the next backs in.

Mistakes That Throw Off Coverage Estimates

The most common error is measuring thickness at the form boards and assuming it holds across the slab. Forms sit on grade stakes at the correct height, but the middle of the excavation often sits lower. Pull a string line across the base at several points and measure down; if the center reads 4.75 inches deep on a 4-inch pour, your real volume is nearly 20 percent higher than planned.

A second mistake is forgetting thickened edges. Many patio and shed slabs call for a perimeter edge 8 to 12 inches deep and 12 inches wide — a monolithic footing. On a 12 x 20 slab, that edge adds roughly half a yard that a flat-slab calculation misses entirely. Third, do not subtract for rebar or wire mesh; the displacement is trivial. And finally, never let the plant talk you into their estimate without checking it yourself. Dispatchers use the same formula you now have, but they do not know your subgrade.

Ordering Tips That Save Money on Pour Day

Call the batch plant with three numbers ready: total yards, mix strength in PSI, and slump. For flatwork, 3,500 PSI with a 4- to 5-inch slump handles nearly every residential job; step up to 4,000 or 4,500 PSI with air entrainment in freeze-thaw climates. Ask what the truck minimum is and whether Saturday delivery carries a premium — it often adds $100 or more.

If your calculation lands awkwardly, say 5.6 yards, order 6 and have a plan for the surplus. Set a small form for a stepping stone, a grill pad, or fence-post footings, and you convert would-be waste into finished work. Concrete you pour is cheap; concrete you turn away still gets billed. Measure twice, add your waste factor, round up to the quarter yard, and the pour will go exactly the way you planned it.

Quick Reference: Bags per Yard and Truck Logistics

Two conversions come up constantly on small jobs. For bagged product, one cubic yard equals 45 bags of 80-pound mix, 60 bags of 60-pound mix, or 90 bags of 40-pound mix — useful when you are deciding whether a repair is a mixer-rental afternoon or a phone call to the plant. For truck planning, remember that a fully loaded mixer weighs 60,000 to 70,000 pounds; it will crack a residential driveway and sink into soft lawn, so plan for the chute’s 12- to 16-foot reach from the street or budget $150 to $300 per hour for a line pump if the pour sits behind the house. Have three people minimum for any pour over 2 yards, screed and bull float staged before the truck arrives, and remember most plants include 4 to 5 minutes of unload time per yard before demurrage charges start. Concrete waits for no one — the coverage math gets you the right volume, and preparation makes sure you can place it before it sets.