Free · Biology and garden models

Bulb Grid Count: Rectangular & Staggered Rows

Calculate bulb grid count: rectangular & staggered rows 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 1 m square with a 10 cm border and 20 cm rectangular spacing holds five by five positions, or 25 bulbs, including the permitted edge positions.

Rectangular rows=floor((W−2b)/r+1); positions/row=floor((L−2b)/s+1). Staggered row separation=0.866s with alternating half-spacing offsets.

Worked example

Enter these known values and leave the other values blank.

Length
1 m
Width
1 m
Border
.1 m
Plant spacing (s)
20 cm
Row spacing (r)
20 cm
Area
1 m²
Number of plants
25

Assumptions and limitations

  • Border is a nonnegative setback on every edge, and spacing is positive. The remaining planting rectangle must be large enough for the selected grid.
  • Staggered rows use the captured approximation 0.866 for √3/2 and alternate a half-spacing horizontal shift. That approximation can affect counts very close to a row boundary.
  • Plant presets and seasonal notes are broad captured scenarios, not cultivar-specific planting instructions. Follow the bulb supplier and local growing guidance.

Common questions

What does this result represent?

Border is a nonnegative setback on every edge, and spacing is positive. The remaining planting rectangle must be large enough for the selected grid.

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. Replace the captured external diagrams with original accessible descriptions of every measurement/grid variant, retaining all variant conditions.

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