Before planting flower pots, containers, boxes or new raised beds, the question arises as to how much soil the respective container can be filled with. Mathematical knowledge is required here. You may still have the formulas for the volume of cubes and cuboids in your head, but things get a little difficult with cones and truncated pyramids.
How to calculate the amount of potting soil for planters?
To calculate the required potting soil for planters, determine the volume based on the shape: truncated cone, truncated pyramid, cube or cuboid. Measure the dimensions, use the appropriate formula and divide the result in cm³ by 1000 to get liters.
What geometric shapes are there in planters?
Everyone knows the normal flower pot, then there are cube-shaped vessels, rectangular planters and those vessels that do not correspond to any geometric shape. An estimate must then be made here. Mathematics helps us to calculate the volume of
- Frustum, this is the normal flower pot
- Pyramid stump, this is the flower pot that resembles a truncated pyramid
- Cubes, available with the patio pots
- Cuboids, these are balcony boxes and raised beds
Calculation of the different volumes
If you want to fill your new planters with potting soil (€10.00 on Amazon), you should determine the amount required beforehand so that there are no leftovers.
Calculation of truncated cones
This mathematical formula is needed for most flower pots.
You measure the height of the pot and multiply the number by the number 3, 14 (pi). The result is divided by 3. The new result is multiplied by the number resulting from the following calculation: r1² + r1 x r2 + r2²Here r1 is the radius of the bottom of the pot and r2 is the radius of the pot opening.
Calculation of truncated pyramid
With the help of a calculator, this complicated formula can be solved quickly. The result is displayed in cm³.
1000 cm³ is 1 liter.
V=h: 3 (G+g +root of g · G)
G stands for the square area the opening of the plant container, calculation side x sideg stands for the square area at the bottom of the plant container, calculation side x side
Calculation cubes
The contents of a cube-shaped planter are easy to calculate. You measure the edge length once and multiply the number by itself three times. The result is cm³ again. Divide by 1000 to get the liters of potting soil required. Volume cube: a x a x a
Calculation cuboid
The cuboid shape is found in flower boxes and many raised beds. Its volume is calculated from the long side a, the short side b and the height h. Here too, the cm³ are divided by 1000 and then result in the contents of the pot in liters. Volume cuboid: a x b x h