How it works
cubic feet = π × (⌀ ÷ 24)² × depthcubic yards ÷ 27 · a 60-lb bag ≈ 0.45 cu ft
- diameter
- the hole width in inches
- depth
- how deep the pour is, in feet
- 0.45
- cubic feet from one 60-lb bag
Bags vary: an 80-lb bag makes about 0.6 cubic feet. Buy 10 percent extra to allow for spillage and holes that flare at the bottom.
Frequently asked questions
How much concrete for a 12-inch, 3-foot hole?
About 2.36 cubic feet, or roughly 5 sixty-pound bags.
How many cubic feet in a 60-lb bag?
About 0.45 cubic feet; an 80-lb bag makes about 0.6.
How many cubic feet in a cubic yard?
Twenty-seven.
Should I buy extra?
Yes, about 10 percent, for spillage and irregular holes.