Flower boxes for the balcony are available in different lengths. Consequently, the amount of potting soil required also varies. If you don't want to buy too much soil, you should be able to calculate the contents of a flower box.
If you want to put plants in the flower box, you should consider their volume
Calculate the volume of a flower box
Anyone who owns a computer has a clear advantage here. The Internet offers so-called "soil volume calculators" on various sites, for example for rectangular planters. You only need the following information for the automatic calculation:
- Length at the top of the jar in cm
- Width at the top of the vessel in cm
- Length at the bottom of the vessel in cm
- Width at the bottom of the vessel in cm
- Length of the inside height in cm
With this information, the computer automatically calculates how much potting soil is required for the box.
Calculate volume yourself
Flower boxes (€16.99) have a wide variety of shapes. The trapezoidal shape is common, but cuboids or cubes are also possible.
In order to calculate the volume of the shapes, the mathematical formulas are needed.
Calculate the volume of the trapezoidal shape
To do this, measure the top width of the box (the distance a), the width of the bottom (the distance b) and the height h. Finally, the total length of the box c is required.
Then use the formula [(a + b):2)] x h x c to calculate the volume in cm³. 1000 cm³ is 1 litre.
Calculate the volume of the cuboid
This is quickly calculated using the values for length (a), width (b) and height (c) and the formula a x b x c , also in cm³.
Calculate the volume of the cube
Since all sides (a) of the cube are the same length, a³ or a x a x a is calculated. The result is again cm³, which can easily be converted into liters.
tip
If you don't want to go to the trouble of calculating the volume of the flower box yourself, you can use the following estimates:
- the usual flower box (16.99 €) with a length of about 80 cm requires about 18 liters of potting soil
- the slightly wider, just as long box needs about 25 liters of soil
- the boxes with water reservoir are 1 m long and need about 24 liters of soil to fill