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Flower Pot Soil Volume Calculator

Estimate the amount of potting soil (in liters) you need from a round pot's rim diameter, base diameter and depth. Supports watering-space deduction and totals for multiple pots.

Input

Assumes a tapered round pot (wider at the rim, narrowing toward the base). It estimates the soil volume from the inner rim diameter, base diameter and depth. Actual amounts vary with pot shape and wall thickness, so treat the result as a rough guide.

cm
cm
cm
cm
Number of pots
pots

Result

Soil volume needed (for 1 pot(s), after deducting watering space)

6.79L

Estimated soil fill depth: 20.0 cm

Volume when full (per pot)

7.67 L

Volume after deduction (per pot)

6.79 L

Total (for 1 pot(s))

6.79 L

Calculation breakdown

Volume when full (per pot)7.67 L
Soil volume after deduction (per pot)6.79 L
Number of pots1 pots
Total soil volume6.79 L

How it works

  • Assumes a tapered round pot shaped like a truncated cone (wider rim, narrower base) and estimates the soil volume from the rim diameter, base diameter and depth (all inside measurements).
  • Shows the actual soil volume after deducting the watering space (the gap between the pot's rim and the soil surface). Leaving about 2-3 cm helps prevent water from overflowing when you water.
  • Pick the number of pots to see the total soil needed when preparing several pots of the same size, giving you a guide to how many liters of potting soil to buy.
  • Wall thickness, inner ridges, and any drainage stones or mesh will shift the amount you actually need. Use the result only as a rough guide.
  • If you only know the radius rather than the diameter, double it before entering. Measuring the inside dimensions where the soil sits, rather than the outside, improves accuracy.