About the Concrete Weight Calculator
This concrete weight calculator works out how heavy a piece of concrete is from its dimensions and density. Choose a rectangular shape (slab, pad, block, beam or footing), a cylinder (pier, column or test cylinder) or enter a volume directly, then pick normal-weight, reinforced or lightweight concrete.
Knowing the weight matters when you plan demolition and hauling (dumpster and trailer limits), check whether a floor, deck or truck can carry a load, size lifting equipment for precast pieces, or budget disposal fees charged per ton. The results are given in pounds, US short tons, kilograms and metric tonnes.
Default densities are typical engineering values: about 145 lb/ft³ for plain normal-weight concrete, 150 lb/ft³ for reinforced concrete (the steel adds weight), and 115 lb/ft³ for lightweight structural concrete made with expanded shale or clay aggregate. Actual density varies with aggregate and moisture, so use the custom option if you know your mix.
With the default inputs, the total weight is 4,833 lb. Change any value above to recalculate instantly.
How to use the concrete weight calculator
- 1Choose the shape: rectangular slab/block, cylinder, or a volume you already know.
- 2Enter the dimensions (feet for length, width and height; inches for thickness and diameter).
- 3Enter how many identical pieces there are.
- 4Pick the concrete type, or enter a custom density if you know it.
- 5Read the total weight in pounds, tons and kilograms, plus the volume.
Formula and method
The calculator finds the volume of one piece in cubic feet — length × width × thickness for a rectangular slab or block (thickness converted from inches), or π r² × height for a cylinder (diameter in inches halved and converted to feet). A known volume in cubic yards is multiplied by 27. The piece volume is multiplied by the number of pieces and by the density of the concrete.
Densities are typical values: plain normal-weight concrete about 145 lb/ft³, reinforced concrete about 150 lb/ft³ (the figure engineers commonly use for dead-load calculations), and lightweight structural concrete about 115 lb/ft³ (its usual range is roughly 90–115). One cubic yard of normal concrete therefore weighs about 27 × 145 = 3,915 lb, close to 2 tons. Pounds are converted to kilograms with 1 lb = 0.45359237 kg.
- L, W
- Length and width (ft)
- T
- Thickness (in)
- D, H
- Cylinder diameter (in) and height (ft)
- n
- Number of pieces
- ρ
- Concrete density (lb/ft³)
Worked examples
10 × 10 ft patio slab, 4 inches thick
The slab is 10 × 10 × 4/12 = 33.33 cu ft (1.235 cu yd). At 145 lb/ft³ that is 4,833 lb, about 2.42 US tons or 2,192 kg. Spread over 100 square feet it adds 48.3 lb/ft² of dead load.
Four 12-inch round piers, 4 ft deep, reinforced
Each pier is π × 0.5² × 4 = 3.14 cu ft, so at 150 lb/ft³ one weighs about 471 lb. Four of them total 12.57 cu ft and about 1,885 lb, just under a ton.
Three cubic yards of lightweight concrete
Three cubic yards is 81 cu ft. At 115 lb/ft³ the load is 9,315 lb, or 4.66 US tons (4.23 metric tonnes) — about 20% lighter than the 11,745 lb the same volume of normal concrete would weigh.
Frequently asked questions
How much does a cubic yard of concrete weigh?+
A cubic yard of normal-weight concrete weighs about 3,900–4,050 lb (roughly 2 US tons), using 145–150 lb per cubic foot × 27 cubic feet. Lightweight structural concrete comes in nearer 3,100 lb per cubic yard.
How much does a concrete slab weigh per square foot?+
Multiply the density by the thickness in feet. A 4-inch normal-weight slab weighs about 48 lb/ft², a 6-inch slab about 73 lb/ft², and an 8-inch slab about 97 lb/ft² at 145 lb/ft³. Reinforced slabs are a little heavier.
Why is reinforced concrete heavier?+
Steel weighs about 490 lb/ft³, more than three times as much as concrete. Typical reinforcement adds a few pounds per cubic foot, which is why engineers often use 150 lb/ft³ for reinforced concrete instead of the 145 lb/ft³ used for plain concrete.
How much does a cubic metre of concrete weigh?+
Normal-weight concrete is about 2,300–2,400 kg/m³ (145–150 lb/ft³), so a cubic metre weighs roughly 2.3–2.4 tonnes. Lightweight structural concrete is about 1,850 kg/m³.
How do I estimate the weight of concrete for demolition?+
Measure the length, width and thickness of each slab, wall or footing, add up the volume and multiply by about 145 lb/ft³. Broken concrete takes up more space than solid concrete, but its weight is the same, and most dumpster and landfill fees are based on weight.