The Soil for Circular Planter calculator computes the volume and associated amount of soil for a circular planter (tapered or straight) based on the (t) top diameter, (b) base diameter and (h) height (see diagram).
INSTRUCTIONS: Choose units and enter the following interior dimensions:
Soil 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.
Potting Mix is combination of organic materials (e.g., peat moss, aged bark and pumice) but no soil (dirt) that is used in lieu of potting soil to improve drainage. Because potting mix has no soil, it tends to be lighter than potting soil and provides a more sterile medium for plants with fewer disease carrying agents. Potting mix is most commonly recommended for plants in containers, and potting mix is particularly desirable for starting seeds.
Garden Soil is a gardening product sold that contains natural soil (dirt) comprised of mixture of loam, clay and sand. Garden soil is often used in raised gardens or planters as a healthy and easy medium for plants and seeds on top of the natural soil in one's yard. Garden Soil differs from Potting Mix in that garden soil contains real soil (dirt), where Potting Mix does not.
Always use local pricing for the most accurate cost! However, vCalc conducts a periodic pricing survey from nationally advertised retailers for various materials. The current Garden Soil Price Survey sample information for Garden Soil and Potting Mix is as follows:
The Pricing Data can be used the the Soil and Planter Calculator calculator. Note, this information is propagated into several pages in vCalc.
IMPORTANT NOTE: Use the interior dimension of the planters and a height to match the depth of soil desired.
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