How Much Does Concrete Weigh? Per Yard, Slab and Bag
Part of the project planner: Planning a concrete patio, slab or driveway.
Normal concrete weighs about 150 pounds per cubic foot, which is 4,050 pounds (2.03 tons) per cubic yard. A 10 × 10 ft slab 4 inches thick weighs 5,000 pounds, or 2.5 tons. This guide has the charts, and the concrete weight calculator does your own sizes.
Weight per square foot by thickness
Each inch of normal concrete adds 12.5 pounds per square foot:
| Thickness | Pounds per ft² | Kilograms per m² |
|---|---|---|
| 2 in | 25.0 lb | 122 kg |
| 3 in | 37.5 lb | 183 kg |
| 4 in | 50.0 lb | 244 kg |
| 5 in | 62.5 lb | 305 kg |
| 6 in | 75.0 lb | 366 kg |
| 8 in | 100.0 lb | 488 kg |
Weight of common slabs
Normal concrete at 150 lb per cubic foot:
| Slab | 4 in thick | 5 in thick | 6 in thick |
|---|---|---|---|
| 10 × 10 ft | 5,000 lb (2.5 tons) | 6,250 lb (3.1 tons) | 7,500 lb (3.8 tons) |
| 12 × 12 ft | 7,200 lb (3.6 tons) | 9,000 lb (4.5 tons) | 10,800 lb (5.4 tons) |
| 20 × 20 ft | 20,000 lb (10.0 tons) | 25,000 lb (12.5 tons) | 30,000 lb (15.0 tons) |
| 24 × 24 ft | 28,800 lb (14.4 tons) | 36,000 lb (18.0 tons) | 43,200 lb (21.6 tons) |
Other types of concrete
| Type | Pounds per cubic foot | Pounds per cubic yard |
|---|---|---|
| Lightweight | 115 | 3,105 |
| Normal | 150 | 4,050 |
| Reinforced (heavily) | 160 | 4,320 |
A 10 × 10 ft slab 4 inches thick would weigh 3,833 pounds in lightweight concrete, against 5,000 in normal concrete.
Why the weight matters
- Supports. A 4 inch slab loads a floor with 50 pounds per square foot before anything is put on it, more than the usual design load for people and furniture in a home. Do not put a slab on a deck, balcony or roof without an engineer's check.
- Ground. Soft soil under a heavy slab needs a thicker gravel base or a wider footing.
- Moving it. A precast step or paver weighs a lot more than it looks: check the weight before you lift it, and use a hand truck or machine.
- Delivery. A full ready-mix truck weighs tens of thousands of pounds, which can damage a driveway, a septic cover or a lawn.
For the cubic yards to order, use the concrete calculator, and for bulk materials see the gravel tons per cubic yard guide. Estimates only.
Frequently asked questions
How much does a cubic yard of concrete weigh?
About 4,050 pounds, or 2.03 tons: 27 cubic feet at 150 pounds per cubic foot. A ready-mix truck carries up to 10 cubic yards, which is about 20 tons of concrete.
How much does a cubic foot of concrete weigh?
About 150 pounds for normal concrete. Lightweight concrete is around 115 pounds, and heavily reinforced concrete about 160.
How much does a 4 inch slab weigh per square foot?
About 50 pounds per square foot: 12.5 pounds for each inch of thickness. A 6 inch slab is 75.0 pounds per square foot.
How much does a 10x10 concrete slab weigh?
A 10 × 10 ft slab 4 inches thick weighs 5,000 pounds (2.5 tons). At 6 inches it weighs 7,500 pounds.
How much does a bag of concrete weigh when it is mixed?
An 80 lb bag makes about 0.6 cubic feet, which weighs about 90 pounds once water is added.
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.