Container Garden Calculator
Calculate how much potting soil you need and how many plants fit in your container.
Enter pot diameter and depth for accurate results.
Container Results
Container Garden calculates soil volume and plant capacity for round pots and planters.
Volume = π × (diameter/2)² × depth
Soil Bags Needed = Volume / Bag Size
Soil volume for common pot sizes:
- 6" pot: 0.1 cu ft (~1 quart)
- 8" pot: 0.2 cu ft (~3 quarts)
- 10" pot: 0.4 cu ft (~1.5 gallons)
- 12" pot: 0.65 cu ft (~2.5 gallons)
- 14" pot: 1.0 cu ft (~4 gallons)
- 18" pot: 1.75 cu ft (~7 gallons)
- 24" pot: 4.0 cu ft (~15 gallons)
Plants per container (by pot size):
- 6–8" pot: 1 plant
- 10–12" pot: 2–3 plants or 1 large
- 14–18" pot: 3–5 plants
- 24"+ pot: 5–8 plants or 1 large shrub
Tips:
- Use potting mix, not garden soil (too heavy for containers)
- Add 1–2 inches of gravel at the bottom for drainage
- Containers dry out faster than garden beds — check daily