Before planting flower pots, tubs, 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 remember the formulas for the volume of cubes and cuboids, but things get a bit difficult with truncated cones and pyramids.
If you don't want too much or too little soil, you should do some calculations before buying the potting soil
What are the geometric shapes of planters?
Everyone knows the normal flower pot, then there are cube-shaped vessels, rectangular planters and vessels that do not correspond to any geometric shape. Then it has to be estimated.
The math helps us further in the volume calculation of
- A truncated cone is the normal flowerpot
- Truncated pyramid, this is the flower pot that resembles a truncated pyramid
- Cubes are available from the patio pots
- Cuboids are balcony boxes (€109.00) and raised beds
Calculation of the different volumes
If you want to fill your new planters with potting soil, the required amount should be determined beforehand so that there are no residues.
Calculation of a truncated cone
This mathematical formula is required for most flower pots.
Measure the height of the pot and multiply the number by 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 + r2²
Here r1 is the radius of the pot bottom and r2 is the radius of the pot opening.
Calculation of the truncated pyramid
With the help of a calculator, even this complicated formula can be solved quickly. The result is displayed in cm³.
1000 cm³ is 1 litre.
V = h : 3 (G+g +root of g G)
G stands for the square area of the opening of the planter, calculation side x side
g stands for the square area at the bottom of the planter, calculation side x side
calculation dice
The content of a cube-shaped planter is easy to calculate. You measure the edge length once and multiply the number three times by itself. The result is again cm³. Divided by 1000 gives the required liters of potting soil.
Volume cube: a x a x a
Calculation cuboid
The cuboid shape is found in flower boxes (€16.99) 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 content of the pot in liters.
Volume cuboid: a x b x h