Question 1

Why does the calculator apply an 85% fill factor?

Accepted Answer

Containers are never filled to the brim — you leave space at the top for watering and to prevent overflow. The 0.85 fill factor is a standard horticultural assumption that gives a realistic usable media volume.

Question 2

How important is drainage for containers?

Accepted Answer

Drainage is critical — without holes, roots sit in waterlogged media and rot within days. Ensure every container has at least one 1–2 cm drainage hole and use a free-draining media mix like cocopeat + perlite.

Question 3

How much media do I need per plant?

Accepted Answer

Leafy greens and herbs need 3–5 L per plant, fruiting crops like tomatoes need 10–15 L, and large fruiting plants like cucumbers need 15–20 L. Use this calculator to match container size to plant spacing.

Pot Volume

Pot Volume