Container shape
There are many different containers types on the market. In our potting soil calculator, you can select between three different shapes. It finds the volume according to the formulas:
rectangular - e.g. raised bed soil containers
volume of rectangular cuboid:
volume = depth * length * width
round
volume of a cylinder:
volume = Ï€ * R² * depth
, whereR
is a radiusflower pot in the shape of truncated cone
volume of a truncated cone:
volume = (1/3) * Ï€ * depth * (r² + r * R + R²)
, wherer
is a radius of the base of flower pot, andR
of top surface radius
If you want to estimate the weight or cost of topsoil, use our soil calculator.
How much soil do I need?
Let's imagine that you want to grow herbs. You have couple small flower pots, and you don't know how much soil do you need. Potting soil calculator can help in that problem:
- Choose the shape of the container.
In our case, it's a flower pot, so we need to calculate the volume of truncated cone. - Enter the dimensions.
For example, assume we have pots with the diameter across top equal to 4 inches, bottom base diameter of 3.2" and height of 2.75". Don't forget that you can select different units, such as centimeter, feet etc. - Set the quantity of the flower pots.
We want to plant oregano, basil, and thyme, so we need to put three in the quantity field. - The volume of soil required is equal to displayed value.
Our calculator is a flexible tool, so you can calculate everything the other way round: if you have a bag of soil and size of your containers, you can estimate how many pots can be filled.
Remember that obtained result represents the volume for the full container. Sometimes you want to fill the container to 4/5, or you already have a plant or tree with the roots and then you will need less soil. The amount of soil may also change as you squeeze it or leave it looser, so presented calculations are only a good estimator.