Concrete is sold by the yard, but the weight behind that volume changes with every batch. A solid cubic yard of standard concrete weighs about 4,050 pounds, yet the exact figure shifts with the mix design, the aggregate type, and the water added at the plant. Finished concrete carries the same density into decorative products such as colorful concrete tiles for floors and walls, so the weight question follows every pour from foundation to finish.
The number matters long before the truck arrives. Cranes, formwork, footings, and floor systems are all sized from the weight the concrete will place on them, so an estimate that misses by a few hundred pounds per yard can under-specify a support system. This article covers the standard weights, the difference between wet and dry concrete, the weight of crushed and broken material, and the calculation method to use on site.
What a Yard of Concrete Weighs in Practice
Concrete is measured by volume everywhere on a project: cubic feet for small pours, cubic yards for truckloads. One cubic yard equals 27 cubic feet. Standard concrete weighs about 150 pounds per cubic foot, which produces the familiar 4,050-pound yard. In US tons, where 1 ton equals 2,000 pounds, that works out to 2.025 tons per cubic yard.
Placement changes the result as much as the mix does. Fresh concrete that is dumped without vibration traps air pockets, while crews that consolidate concrete in congested reinforced concrete members push trapped air out and raise the density of the finished slab. A well-consolidated yard lands near the theoretical maximum; a honeycombed one comes in lighter while hiding voids that later inspections will find.
The Role of Density in Concrete Weight
Density is the bridge between volume and weight. The cement paste binds the mix together, but the aggregate dominates the scale: crushed stone and gravel weigh more than the sand and paste around them. A mix built on granite or trap rock runs toward the heavy end of the range, while porous aggregates such as pumice or expanded clay pull a yard down by hundreds of pounds.
Why Volume Measurements Vary
Volume is simple to measure and simple to get wrong. Multiply length by width by thickness, or take the square footage and multiply by the height, to get cubic feet, then divide by 27 to convert to cubic yards. A 10-foot by 10-foot slab at 4 inches thick holds 33.3 cubic feet, or 1.23 cubic yards, which weighs roughly 5,000 pounds.
Weight by Mix Strength
Specified strength, measured in pounds per square inch, tracks density closely. The link between concrete strength and porosity explains why a stronger mix usually weighs more per yard: higher-strength concrete carries more cement and less water, and the denser paste leaves fewer voids for air and moisture. The table below gives typical figures for common mixes.
| Mix Strength | Density (lb per cu ft) | Weight per Cubic Yard | Tons per Cubic Yard |
|---|---|---|---|
| 3,000 psi | about 145 | about 3,915 lb | about 1.96 tons |
| 4,000 psi | about 150 | about 4,050 lb | about 2.03 tons |
| 5,000 psi | about 152 | about 4,100 lb | about 2.05 tons |
| Lightweight mix | 90 to 115 | 2,430 to 3,105 lb | 1.2 to 1.6 tons |
How Aggregate Content Shifts Weight
Most of the spread between mix strengths comes from the stone. A 3,000 psi yard uses a leaner paste and slightly less coarse aggregate, so it weighs a little less than a 4,000 psi yard. A 5,000 psi mix adds more cement and a tighter gradation, pushing the yard past the 4,050-pound mark.
Lightweight and Heavyweight Mixes
Designers can move the scale in either direction on purpose. Lightweight concrete made with expanded shale or clay weighs 90 to 115 pounds per cubic foot, which cuts dead load on high-rise floors. Heavyweight concrete made with iron ore or barite aggregate can exceed 200 pounds per cubic foot and is specified for radiation shielding in hospitals and laboratories.
Wet Concrete Versus Dry Concrete
Water is the lightest ingredient and the easiest to misjudge on the scale. One gallon of water weighs 8.34 pounds, and a typical yard needs 20 to 25 gallons, adding roughly 170 to 210 pounds before the mix leaves the plant. That is a small share of the 4,050-pound total, but it explains the gap between a fresh load and a cured slab.
A yard of wet concrete weighs about 4,150 pounds at placement. As the mix hydrates, excess water evaporates, and a typical yard loses 10 to 14 gallons in the first weeks, which drops the weight back toward the 4,050-pound dry figure. The arithmetic fits: 10 to 14 gallons at 8.34 pounds per gallon equals 83 to 117 pounds of lost water.
Moisture keeps changing the weight long after the pour. When you pour new concrete over old concrete, the moisture state of the base slab controls how much water the fresh layer gives up, so the bond and the final weight both depend on surface preparation. Wet subgrades slow evaporation and keep the slab heavier for longer.
How Water Weight Changes Over Time
Evaporation is fastest in the first 28 days, when hydration is most active, and the slab settles into its service weight near 4,050 pounds per yard. Sealed or coated concrete holds more moisture, which is why a vapor-barrier floor weighs more in calculation than an identical exposed slab. Factors that keep a yard heavy include:
- High water-cement ratio mixes that hold more evaporable water
- Sealed or coated surfaces that trap moisture
- Cold or humid weather that slows drying
- Thick sections that dry from the surface only
Crushed, Broken, and Recycled Concrete
Demolition changes the numbers completely. Broken concrete in place weighs about 2,025 pounds per cubic yard, roughly half the solid figure, because the rubble leaves air gaps between pieces. A cubic foot of damaged concrete runs about 75 pounds, compared with 150 pounds for a solid cubic foot. Once crushed and compacted into a base layer, the material tightens to about 1 ton per cubic yard, or 2,000 pounds, still well below a solid slab.
Those figures guide both disposal and reuse. Dumpsters are rented by volume but trucks are limited by weight, so a yard of broken concrete at 2,025 pounds fills the container without the axle loads that solid pieces would create. Run a quick post-concrete inspection testing routine on the damaged slab before deciding whether the pieces are clean enough to crush and reuse as aggregate.
Half Yard and Quarter Yard Quantities
Small repairs order fractions of a yard. A half yard of solid concrete weighs about 2,025 pounds, and a quarter yard comes to roughly 1,013 pounds. For dry concrete sand, plan on about 2,700 pounds per cubic yard, and for aggregate base, figure roughly 1.4 tons per cubic yard before compaction.
Calculating Weight for Slabs, Footings, and Orders
One three-step method covers any shape. Measure the volume in cubic feet, convert to cubic yards, then multiply by the density of the mix you ordered.
- Measure the footprint in feet: length times width.
- Find the volume: multiply length by width by thickness in feet, where 4 inches equals 0.333 feet.
- Convert to cubic yards: divide the cubic feet by 27.
- Multiply by the mix weight: 4,050 lb per cubic yard for standard 4,000 psi concrete, or 150 lb per cubic foot.
- Add waste: order 5 to 10 percent extra for uneven ground and spillage.
A 20-foot by 12-foot patio slab at 4 inches thick holds 80 cubic feet, or 2.96 cubic yards, and weighs about 12,000 pounds. Spread over the ground, that is 50 pounds per square foot, a load the soil and subgrade must carry without settlement.
Weight Per Square Foot at Common Thicknesses
Each inch of slab adds 12.5 pounds per square foot, because 150 pounds per cubic foot divided by 12 inches equals 12.5. The table below lists the common cases.
| Slab Thickness | Weight per Square Foot |
|---|---|
| 3 inches | 37.5 lb |
| 4 inches | 50 lb |
| 5 inches | 62.5 lb |
| 6 inches | 75 lb |
| 8 inches | 100 lb |
Estimating a Truckload
Ready-mix trucks carry 9 to 11 cubic yards, which translates to 36,450 to 44,550 pounds of wet concrete. A 10-yard load at 4,150 pounds per yard weighs about 41,500 pounds, so verify driveway and road ratings before scheduling a delivery. For masonry work the math shifts to units, because hollow concrete blocks and solid concrete blocks carry different weights per square foot of wall and different mortar takeoff.
Choosing the Right Concrete for the Job
Weight is a design input, not just a billing quantity. For long-span floors, designers often select prestressed concrete over reinforced concrete because the prestressed sections are slimmer and lighter per square foot while carrying the same loads. The saved dead load lets the supporting frame use smaller columns and footings.
On the low-cost end, leaner mixes serve where strength is not needed. Where a slab supports no structure, the choice between lean concrete versus normal concrete sets both the weight per yard and the material cost, because lean concrete carries less cement and more aggregate. A blinding layer under a footing does its job at lower weight and lower price than a full structural mix.
Matching Weight to Your Site Conditions
Before ordering, confirm the mix density with the supplier and the load path with the structural drawings. Soft soils, existing slabs, and lifting equipment all have limits expressed in weight, and the gap between a 3,915-pound yard and a 4,100-pound yard is easy to overlook in the field but hard to correct after placement. Keep the 4,050-pound figure as the planning baseline, adjust it for the mix and moisture state, and the concrete will never surprise the people who have to move or support it.