How Much Does a Yard of Concrete Weigh? (Full Spec)

To understand concrete mass, we look at dimensional geometry and volumetric density under ASTM C138 (Standard Test Method for Density, Yield, and Air Content of Concrete). A cubic yard measures 3 feet wide by 3 feet long by 3 feet high:

Standard residential and commercial structural concrete incorporates crushed limestone or river gravel aggregates, washed coarse sand, Portland cement (ASTM C150 Type I/II), and batch water. Consolidated ready-mix concrete has a mass density between 145 and 150 pounds per cubic foot (pcf). Multiplying this density across 27 cubic feet yields:

If steel reinforcement (rebar cages, welded wire mesh) is installed, reinforced concrete dead loads are conventionally calculated by civil and structural engineers at 150 to 155 pcf (roughly 4,185 lbs/yd³) to account for the steel density of 490 lbs/cu ft.

Concrete density is primarily determined by aggregate selection, which occupies 60% to 75% of the total mix volume. The American Concrete Institute (ACI 213R) recognizes three primary density categories:

Why do transit mix delivery tickets show higher weights than dry structural engineering tables? The answer lies in the hydration chemistry of Portland cement:

• Wet, Freshly Placed Concrete (4,150 – 4,200 lbs/yd³): When concrete is discharged from the chute, it contains all the batch water required for chemical hydration and mechanical slump placement (typically a water-to-cement ratio between 0.40 and 0.50, equating to 250 to 300 lbs of water per cubic yard).
• Cured Concrete at 28 Days (4,050 lbs/yd³): As the calcium silicate hydrate (C-S-H) gel crystalline matrix matures, approximately 50% of the initial mix water chemically binds into the permanent mineral structure.
• Oven-Dry / Equilibrium Concrete (3,900 lbs/yd³): Over months or years in heated residential or commercial structures, unbound evaporable water leaves the capillary pores, resulting in an ultimate long-term equilibrium weight reduction of 3% to 4%.

A common contractor and DIY dilemma is deciding between hauling bagged concrete from the home improvement center or ordering ready-mix delivery. Understanding the haul weight is critical for truck safety:

Pickup Truck Warning: A standard half-ton pickup (Ford F-150, Chevy Silverado 1500, Ram 1500) has a typical payload capacity of 1,600 to 2,100 lbs. Loading 45 bags of 80 lb concrete (3,600 lbs) will severely crush the suspension, blow tires, and void warranties. Hauling 1 full cubic yard in bagged form requires a 1-ton pickup (F-350 / 3500 series) or two balanced trips in a 3/4-ton truck.

Formwork carpenters and foundation contractors must understand concrete weight because wet concrete acts as a heavy fluid exerting lateral hydrostatic pressure against vertical wall forms. According to ACI 347R (Guide to Formwork for Concrete):

For an 8-foot-tall foundation wall placed rapidly without setting, the hydrostatic head pressure at the bottom of the form reaches 1,200 pounds per square foot (psf). Inadequate snap-ties, walers, or strongbacks will experience catastrophic blowout under this immense hydrostatic tonnage.

Let's calculate the total concrete volume, weight, and subbase load for a standard residential two-car garage slab measuring 24 feet by 24 feet poured 4 inches thick:

1. Calculate Slab Surface Area:24 ft × 24 ft = 576 square feet.
2. Calculate Cubic Volume:576 sq ft × (4 / 12) ft = 192 cubic feet.
3. Convert to Cubic Yards: 192 / 27 = 7.11 cubic yards. Adding a standard 10% allowance for grade variations and spillage gives 7.82 cubic yards (rounded to an 8.0-yard truck order).
4. Compute Total Mass: 7.82 cu yd × 4,050 lbs/cu yd = 31,671 pounds (15.84 short tons).
5. Subgrade Soil Bearing Load: 31,671 lbs ÷ 576 sq ft = 55 psf dead load transmitted to the compacted gravel subbase.