Choose the closest shape
The planner supports a straight-sided round pot, a rectangular box and a tapered round pot. Real containers may have curved bases, raised floors or internal reservoirs. Use a measured capacity from the manufacturer when geometry is a poor description.
Keep the units together
Measure interior dimensions in centimetres or inches, according to the selected mode. The output is litres or US gallons. For a tapered round pot, measure the top and bottom internal diameters and the full internal height; the tool interpolates the diameter at the chosen fill line.
Allow for the space you are not filling
Enter headroom above the mix and an estimated volume already occupied by root balls or retained growing medium. Those allowances are separate. The tool reports the geometric volume to the fill line and the remaining mix estimate so you can see the subtraction.
Plan the purchase and the position
Round up using the bag size you enter. The result does not account automatically for compaction, settling or a manufacturer’s compression ratio. It also does not calculate wet weight or confirm that a balcony, shelf or support can carry the load.
Plant advice needs the species or cultivar, local climate, light and growing conditions. Photographs of a generated garden are mood imagery, not observations of a growing trial.
