The Circular Planter Volume calculator computes the volume (V) of a cylindrical or V-shaped planter based on the (t) top diameter, (b) base diameter and (h) height (see diagram).
INSTRUCTIONS: Choose units and enter the following:
Volume (V): The calculator returns the volume in cubic feet. However, this can be automatically converted into other volume units via the pull-down menu next to the answer. The calculator also returns the number of soil bags of the following sizes:
IMPORTANT NOTE: To compute the amount of soil needed in the planter, use the interior dimensions of the container, and use the top diameter associated with how high you want to fill the container. If you wish to fill to the brim, it is the full inner height.
The formula for the volume of a circular planter is as follows:
`v = 1/12⋅π⋅h⋅(t^2+t⋅b+b^2)`
This answers the following questions:
If you do not intend to fill the container to the top, this formula will over estimate unless you use a height (h) and top (t) that match your expected top surface inside the container. Unless it's a very large container, and/or you are only using a small portion of the container, the overage should be small.
The Garden Soil Price Survey information is as follows:
The Pricing Data can be used the thecalculator.
Other Planter Shapes
Or just use the single calculator with all of the shapes available in one place at. This includes some useful industry data like potting soil pricing from national advertisers.