Concrete Weight Per Cubic Foot
Concrete weight matters more often than people expect — sizing a dumpster, checking whether a trailer axle can handle a load of broken slab, or confirming that a deck or garage floor can carry a topping pour. The short answer is about 150 pounds per cubic foot, but the useful answer depends on the mix, the reinforcement, and whether the concrete is intact or demolished.
Weight by concrete type
Density varies with the aggregate used and whether steel reinforcement is included. These are the figures used for typical estimating work in the US:
| Concrete Type | lb per Cubic Foot | lb per Cubic Yard | Tons per Cubic Yard |
|---|---|---|---|
| Normal-weight, plain | 145 | 3,915 | 1.96 |
| Normal-weight, reinforced | 150 | 4,050 | 2.03 |
| Structural lightweight | 90–115 | 2,430–3,105 | 1.22–1.55 |
| Broken concrete, loose | 75–100 | 2,025–2,700 | 1.01–1.35 |
| Crushed concrete, compacted | 120–140 | 3,240–3,780 | 1.62–1.89 |
The 150 lb/cf figure for reinforced concrete is the standard design assumption — the steel adds a few pounds per cubic foot over plain concrete. For quick field math, 4,000 pounds per cubic yard is close enough and easy to remember.
The formula
Does PSI change the weight?
Barely. Compressive strength is governed mainly by the water-to-cement ratio and the cement content, not by density. A 3,000 psi mix and a 4,500 psi mix both land in the same 145 to 150 lb/cf band — the difference is typically under 2 percent and is not worth adjusting for in estimating.
For context on where each strength is used: 2,500 to 3,000 psi is typical for footings and non-structural pads, 3,000 to 3,500 psi for interior slabs and patios, 4,000 psi for driveways and garage floors, and 4,500 psi and above for freeze-thaw exposure and heavy commercial work. Choose strength on performance grounds and assume the weight stays the same.
Lightweight concrete is the real exception. By substituting expanded shale, clay, or slate for normal aggregate, density drops to 90 to 115 lb/cf — roughly 25 to 35 percent lighter. That is why it appears in elevated decks and topping slabs where dead load is the governing constraint.
Worked example: a 24x24 slab
- Area: 24 x 24 = 576 square feet
- Volume at 4 inches: 576 x 0.333 = 192 cubic feet
- Weight at 150 lb/cf: 192 x 150 = 28,800 pounds
- Converted to tons: 28,800 / 2,000 = 14.4 tons
The same slab at 6 inches thick weighs 288 x 150 = 43,200 pounds, or 21.6 tons. Those numbers explain why demolition is priced by weight and why a single slab can fill several dumpsters.
Demolition and disposal planning
Broken concrete occupies more space than intact concrete because of the voids between pieces, so loose rubble runs 75 to 100 lb/cf. A 10-yard dumpster rated for concrete typically holds around 10 tons, meaning that 4-inch 24x24 slab needs roughly one and a half dumpsters.
Concrete-only dumpster rentals generally cost $350 to $700 in 2026, and many landfills charge $40 to $100 per ton for clean concrete. Recycling yards often accept clean, rebar-free concrete at a lower rate or occasionally free, since it is crushed into aggregate base — worth a phone call before you book a landfill run.
Also check trailer capacity. A typical half-ton pickup handles roughly 1,000 to 2,000 pounds in the bed, which is only about 7 to 13 cubic feet of concrete. Overloading is the most common mistake on DIY demolition days.
Structural load checks
If you are pouring over a wood-framed deck or an existing floor, weight becomes a structural question. A 2-inch topping slab adds about 25 pounds per square foot — significant against a residential live load allowance that is often around 40 pounds per square foot. Have an engineer confirm before adding a topping pour to any elevated structure.
For related takeoffs, size your pour with the Concrete Slab Calculator, estimate masonry units with the Brick Calculator, or explore all of our concrete and masonry calculators.