(Pi)R2 x L = Cubic Feet
Pi = 3.14
R2 = 1/2 Diameter/12 (example: 1/2 of 12" = 6, 6/12 = .5)
L = Length of Cylinder
Cubic Yards= Cubic Feet/27
The formula for a 10" Sonotube 3’ deep would be as follows:
3.14 x (.42 x .42) x 3 = 1.66CF/27 = .062CY
Good Luck, hope this helps!
In doing Concrete work there are two major volume calculations needed:
Formulas:
Rectangular solid: Length x Width x Height = Volume
Simplified: L x W x H x = V
Cylinder: This can be written two ways, both are listed.
One way: radius squared x Pi (3.14) x Height = Volume
Simplified: r2 x 3.14 x H = V
The other way: (1/2 the diameter) squared x Pi (3.14) x H = V
Simplified: (1/2d)2 x 3.14 x H = V
The point to remember about these formulas is when speaking of a circle 1/2
the diameter is the radius, so both formulas are saying the same thing.
I hope this Okay