Free · Biology and garden models

Raised-Bed Volume & Material Shares

Calculate raised-bed volume & material shares with the retained input modes, unit choices and stated arithmetic assumptions.

  • Formula & worked example
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A 2 m by 1 m bed filled 20 cm deep holds 0.4 m³. A 60/30/10 mix divides that into 0.24, 0.12 and 0.04 m³.

V=N L W h; each constituent volume = V × its fraction; fractions sum to one.

Worked example

Enter these known values and leave the other values blank.

Length
2:0 m / cm
Width
1:0 m / cm
Depth
20 cm
How many raised beds?
1
Soil mix
60% topsoil - 30% compost - 10% aeration
Volume of soil needed
0.4 m³
Base material volume (topsoil or peat/coir)
0.24 m³
Compost volume (selected mix)
0.12 m³
Others
0.04 m³

Assumptions and limitations

  • The result splits the geometric fill volume among the selected material shares. Settling, bag losses, existing material and drainage layers are omitted.
  • Preset shares are mixing scenarios, not universal soil recipes. The first fraction denotes the base material in the selected scenario; the third recipe uses peat/coir rather than topsoil.
  • For a custom mixture, enter percentages between 0 and 100 that sum to 100. Equal-thirds arithmetic must balance the final rounding remainder.

Common questions

What does this result represent?

The result splits the geometric fill volume among the selected material shares. Settling, bag losses, existing material and drainage layers are omitted.

Can I solve for another quantity?

Enter the known quantities and clear the unknown where an inverse relationship is available. Selection presets remain separate from measurements you supply; use locks to retain known inputs.

References

Bookify enforces finite physical or discrete inputs for this model and detects the stated selected-scenario relationships without changing the captured arithmetic graph. Balance the equal-thirds preset at the captured arithmetic precision: two rounded thirds and the remaining fraction sum to exactly one instead of the captured 0.9999.

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