SMALL TOOLS. USEFUL ANSWERS.
A little room to grow.
Estimate the potting mix for a rectangular planter or a round, straight-sided pot.
A few useful details
How is the estimate calculated?
Rectangular volume = length × width × fill depth. A round pot uses π × (diameter ÷ 2)² × fill depth. Cubic centimetres are divided by 1,000 to give litres. Inch measurements are converted using exactly 2.54 cm per inch. Bags are rounded up to a whole bag.
Does this work for tapered pots?
The round-pot option assumes a cylinder. For a tapered pot it will only be a rough approximation. Use a volume marked by the manufacturer or measure the actual shape for a better estimate.
Does it tell me when to water?
No. Watering depends on the plant, growing medium, weather, and container. Check the plant and medium rather than using container volume as a watering schedule.