The calculator collection

Soil, mulch, plant spacing & watering calculators

Work out what fits in your growing space, how much material to bring home, and how much water a drip session delivers. Choose a tool based on the shape of the space and what you are adding.

Explore the tools

8 calculators

Choose the right calculator

Covering the top of a garden bed

Enter surface dimensions and the depth of the mulch layer. Compare bags with a bulk cubic-yard order.

Filling a rectangular raised bed

Use the inside dimensions and the remaining fill depth. A top-up needs only the depth of new soil.

Filling a tapered round pot

Measure the inside diameters at the bottom and at the fill line. A tapered pot holds less than a cylinder of its top diameter.

Arranging plants in a bed

Use center-to-center spacing and an explicit edge margin for a rectangular grid.

Put the numbers to work

  1. Calculate the soil to add
  2. Count planting positions
  3. Estimate water delivered

Material volume and watering requirements are different questions. The irrigation tool estimates delivered water; it does not prescribe what a plant needs.

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Clear formulas and useful worked examples.

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