Concrete Weight Calculator
Short answer: a 10 × 12 ft slab at 4 inches thick weighs about 6,000 lb (3 tons) at normal density. Enter your slab and density below.
Calculate the weight
How the calculation works
Volume = length × width × thickness, all in feet (thickness in inches ÷ 12). Weight = volume × density.
Worked example: a 10 × 12 ft slab at 4 in thick = 10 × 12 × (4 ÷ 12) = 40 cu ft. At 150 lb per cubic foot: 40 × 150 = 6,000 lb = 3 tons = about 2,722 kg.
Weight of common slabs (150 lb per cubic foot)
| Slab | Thickness | Weight |
|---|---|---|
| 10 × 10 ft | 4 in | 5,000 lb (2.50 tons) |
| 12 × 12 ft | 4 in | 7,200 lb (3.60 tons) |
| 20 × 20 ft | 4 in | 20,000 lb (10.00 tons) |
| 10 × 12 ft | 6 in | 9,000 lb (4.50 tons) |
At normal density, concrete weighs 50 lb per square foot at 4 inches thick and 75 lb per square foot at 6 inches thick.
Frequently asked questions
How much does a cubic yard of concrete weigh?
About 4,050 lb (2.03 tons) for normal-weight concrete at 150 lb per cubic foot. Lightweight mixes weigh less — check the mix density.
How much does a 10x12 concrete slab weigh?
At 4 inches thick and normal density: 40 cu ft × 150 lb = 6,000 lb, or 3 tons.
How much does concrete weigh per square foot?
At normal density: 50 lb per square foot at 4 inches thick, 75 lb at 6 inches. Multiply density by thickness in feet.