Weight of a cubic yard of concrete
A cubic yard of concrete weighs about 3,780 pounds. One manufacturer's data sheet gives the typical unit weight of its standard packaged concrete mix as approximately 140 lb per cubic foot (2,242.5 kg/m³), measured to ASTM C138.[1] A cubic yard is 27 cubic feet, so 140 × 27 = 3,780 lb.[3]
| Volume | Pounds | Kilograms | US tons |
|---|---|---|---|
| 1 cubic foot | 140 | 63.5 | 0.07 |
| 1 cubic yard (27 cu ft) | 3,780 | 1,715 | 1.89 |
| 1 cubic meter | 4,944 | 2,243 | 2.47 |
Concrete made with ordinary sand and stone is called normal-density concrete. The American Concrete Institute describes low-density ("lightweight") concrete as usually 90–115 lb/ft³ and high-density concrete as about 180–350 lb/ft³;[2] ordinary concrete falls between the two. Mixes differ, so for a structural calculation use the unit weight your supplier reports for your mix.
A cross-check: 45 bags of 80 lb mix make a cubic yard (3,600 lb of dry mix), and each bag takes about 6 pints of water,[1] roughly 281 lb in total. Together that is about 3,881 lb, within a few percent of 3,780.
How much does a yard of concrete cover?
One cubic yard covers 81 square feet at 4 inches thick. Coverage is 324 ÷ thickness in inches, the same rule as any other material, because a cubic yard spread 1 inch thick covers 324 sq ft.
| Thickness | Square feet | Square meters | Weight per sq ft |
|---|---|---|---|
| 2 in | 162 | 15.1 | 23 lb |
| 3 in | 108 | 10 | 35 lb |
| 4 in | 81 | 7.5 | 47 lb |
| 5 in | 64.8 | 6 | 58 lb |
| 6 in | 54 | 5 | 70 lb |
| 8 in | 40.5 | 3.8 | 93 lb |
The manufacturer specifies its standard mix for pours 2 inches (50 mm) thick or more.[1] The last column is useful for checking loads: a 4-inch slab weighs about 47 lb per square foot.
Bags of concrete per cubic yard
An 80 lb bag of standard concrete mix yields about 0.60 cubic feet, so a cubic yard takes 45 bags.[1]
| Bag | Yield | Bags per cubic yard | Bags per m³ |
|---|---|---|---|
| 40 lb (18.1 kg) | 0.3 cu ft (8.5 L) | 90 | 118 |
| 50 lb (22.6 kg) | 0.375 cu ft (10.6 L) | 72 | 94 |
| 60 lb (27.2 kg) | 0.45 cu ft (12.7 L) | 60 | 79 |
| 80 lb (36.2 kg) | 0.6 cu ft (17 L) | 45 | 59 |
| 90 lb (40.8 kg) | 0.675 cu ft (19.1 L) | 40 | 52 |
Yields are approximate, so round up and keep a bag or two spare. Converting other volumes is easiest with the cubic feet to cubic yards converter.
Estimating the weight of a slab
Multiply length × width × thickness, convert to cubic yards, then weight and bags follow. The calculator at the top of the page does this for rectangles, circles (round footings and pads) and triangles; for walls, steps and post holes, use the concrete calculator.
cubic yards = length (ft) × width (ft) × thickness (in) ÷ 324
- 10 × 10 ft patio, 4 in: 1.23 yd³, about 4,667 lb, 56 bags of 80 lb.
- 12 × 20 ft pad, 4 in: 2.96 yd³, about 5.6 US tons.
- Round footing 1 ft across, 3 ft deep: 2.36 cu ft, about 330 lb, 4 bags of 80 lb.
To price the job, enter your quotes in the concrete slab cost calculator. The base underneath is a separate job; the gravel depth guide and the paver base calculator cover compacted aggregate, and the main cubic yard calculator handles any loose material.
Heavy loadsAt about 1.9 US tons per cubic yard, even a small trailer load of concrete can exceed what a vehicle is rated to carry. Check the rating before hauling.
Frequently asked questions
How much does a yard of concrete weigh in tons?
About 1.9 US tons (3,780 lb), or about 1.7 metric tonnes, at a typical 140 lb per cubic foot.[1]
How much does a yard of concrete cover?
81 sq ft at 4 inches thick, 108 sq ft at 3 inches and 54 sq ft at 6 inches.
How many 80 lb bags of concrete make a yard?
45 bags, since each yields about 0.60 cubic feet.[1]
How much does a cubic foot of concrete weigh?
About 140 lb for a standard packaged mix.[1]
How much does a 60 lb bag of concrete make?
About 0.45 cubic feet (12.7 L), so 60 bags make a cubic yard.[1]