Cubic yards calculator
Length times width times height in feet, converted to cubic yards. Works on a debris pile, a slab you are about to break up, or a room you are about to gut.
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This calculator needs JavaScript. The reference table below covers the same ground.
How many cubic yards is my debris pile? cubic yards = (length ft × width ft × height ft) ÷ 27, because there are 27 cubic feet in a cubic yard. For a slab, use the thickness in inches divided by 12 as the height.
The formula
cubic yards = (length ft × width ft × height ft) ÷ 27, because there are 27 cubic feet in a cubic yard. For a slab, use the thickness in inches divided by 12 as the height.
Worked example
A 20 by 20 foot patio slab, 4 inches thick: 20 × 20 × 0.333 ÷ 27 = 4.9 cubic yards. At roughly two tons per yard that is about 10 tons of concrete — which is why this job takes several 10 yard containers and not one 40.
Assumptions
- 27 cubic feet to a cubic yard is exact arithmetic, not an estimate
- A measured pile is loose volume and includes air. Broken-up material occupies more space than it did intact — typically 30 to 60% more for masonry
Reference table
| Slab area at 4 in thick | yd³ | Approx tons of concrete |
|---|---|---|
| 100 ft² | 1.23 | 2.5 |
| 200 ft² | 2.47 | 4.9 |
| 400 ft² | 4.94 | 9.9 |
| 600 ft² | 7.41 | 14.8 |