Enter the size of a slab, pad or block and choose the type of concrete. The calculator works out the volume and multiplies it by the unit weight to give the weight in pounds, US tons and kilograms, which is useful for demolition, hauling and lifting.
Concrete weight formula
Volume (cu ft) = length × width × thickness, all in feet Weight (lb) = volume × unit weight (lb per cu ft) Tons = pounds ÷ 2,000
The Federal Highway Administration uses 145 lb per cubic foot for normal-weight concrete. Steel reinforcement adds a little weight, which is why 150 lb per cubic foot is a common estimate for reinforced concrete. Lightweight structural concrete made with lightweight aggregate weighs considerably less; the 115 option is a rough estimate, so check the mix design if it matters.
Worked example: a 10 × 10 ft slab, 4 in thick
- Volume: 10 × 10 × (4 ÷ 12) = 33.33 cu ft.
- Weight: 33.33 × 145 = 4,833 lb.
- That is 2.42 US tons or 2,192 kg.
Weight per cubic yard and per square foot
| Measure | Weight at 145 lb/cu ft |
|---|---|
| 1 cubic foot | 145 lb |
| 1 cubic yard (27 cu ft) | 3,915 lb (1.96 tons) |
| 1 sq ft of 4 in slab | 48.3 lb |
| 1 sq ft of 6 in slab | 72.5 lb |
Questions
How much does a yard of concrete weigh?
About 3,915 lb, or just under 2 US tons, for normal-weight concrete.
How heavy is a 4 in slab per square foot?
About 48.3 lb.
Can my truck haul broken concrete?
Compare the weight with your truck’s payload rating; a cubic yard of solid concrete is close to 2 tons.
Sources
- FHWA-HRT-05-057, Appendix C, Federal Highway Administration.
Used for: Normal-weight concrete taken as 145 lb per cubic foot. - NIST Guide to the SI, Appendix B.8: Factors for units listed alphabetically, National Institute of Standards and Technology.
Used for: Pound to kilogram conversion.