Calculator

Fairy Garden Calculator Soil, Plants & Gravel for Any Container

Enter your container size to get how much soil it holds, how many mini plants or succulents fit, and how much gravel you need.

Your project

in
in
Result
Enter your measurements above and click Calculate.

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How it works

soil = area × usable depth × 1.18 ÷ 67.2 (dry quarts); plants = area ÷ spacing²

Soil & plants by round container size

Soil & plants by round container size
Bowl diameterDepthPotting soilSmall plugs that fit
6 in3 in0.2 dry qt3
8 in4 in1.3 dry qt5
10 in4 in2.1 dry qt8
12 in5 in5.0 dry qt12

Soil is sold in dry quarts and cubic feet (1 cu ft = ~25.7 dry quarts). Counts assume small 2-inch plugs at 3-inch spacing; pack succulents closer for a fuller look.

Frequently asked questions

How much soil does a fairy garden need?
It depends on the container. A 12-inch bowl 5 inches deep holds about 5 dry quarts of potting soil; an 8-inch bowl needs only about 1.3 dry quarts. Subtract about an inch for a gravel drainage layer and an inch of rim.
How many succulents fit in a 12-inch bowl?
Packed root-to-root, about 28 small succulents fit in a 12-inch round bowl; spaced to grow, around 12–16. For a lush instant look, plant them close — succulents tolerate tight quarters.
Do fairy gardens need drainage?
Yes. Use a pot with a drainage hole and a 1–2 inch gravel layer on the bottom, plus a fast-draining cactus/succulent mix. In a sealed container, add a layer of activated charcoal and water sparingly.

Estimates are guidance only — material quantities vary by project conditions. Always confirm with a professional before purchasing.