Potting Soil Calculator Calculator

in
For round pots, enter diameter.
in
Not used for round pots.
in
Biology

Calculate the volume of potting soil needed to fill a rectangular planter or round pot.

Formula

Rectangle: L×W×D; Round: π×r²×D; Convert cu in ÷ 1728 = cu ft
  • Fill soil to 1–2 inches below the rim to prevent overflow when watering.
  • 1 cubic foot ≈ 25.71 dry quarts (most potting soil bags are listed in quarts or cubic feet).
  • Typical potting soil bags: 8 qt, 16 qt, 2 cu ft.

24×12×10 in rectangular planter

Inputs
  • Container Shape: rectangle
  • Length (or Diameter): 24 in
  • Width: 12 in
  • Depth to Fill: 10 in

24×12×10 = 2,880 cu in. 2,880÷1728 ≈ 1.67 cu ft ≈ 43 quarts.

Frequently asked questions

How much does a bag of potting soil cover?
A 2 cu ft bag fills roughly a 12×12×24 in planter to the top.
Should I use potting mix or garden soil?
Use potting mix for containers — it drains better and is lighter than garden soil.