Weight concrete calculator
What you need
4.94 cu yd
- Cubic feet
- 133.33 cu ft
- Cubic metres
- 3.776 m³
- Order this much
- 5.43 cu yd
- 80 lb bags
- 245
- 60 lb bags
- 326
- Weight
- 18,670 lb
- Truckloads
- 1
Common sizes
| Size | Cubic yards | 80 lb bags |
|---|---|---|
| 20×20, 4″ | 4.94 | 245 |
| 20×20, 5″ | 6.17 | 306 |
| 20×20, 6″ | 7.41 | 367 |
| 20×20, 8″ | 9.88 | 489 |
| 24×24, 4″ | 7.11 | 353 |
| 24×24, 6″ | 10.67 | 528 |
How this is worked out
volume in cubic feet = width in feet × length in feet × thickness in inches ÷ 12
cubic yards = cubic feet ÷ 27
bags = cubic feet with waste ÷ what one bag yields, rounded up
At the dimensions above that is 133.33 cubic feet, which is 4.94 cubic yards.
Questions
How much concrete do I need for a 20 × 20 ft slab 4 in thick?
4.94 cubic yards, which is 133.33 cubic feet before any waste allowance.
How many bags of concrete is that?
245 eighty-pound bags, or 326 sixty-pound bags, with 10% waste allowed for.
What does that much concrete weigh?
About 18,670 pounds, at 140 pounds per cubic foot.
Is that a full truckload?
It is 1, once waste is allowed for. A full truckload is typically about 10 cubic yards.
This site works out quantities. It does not tell you what thickness, reinforcement or sub-base your job needs — those depend on local code and on the load.