Plant Spacing Calculator

How to use the plant spacing calculator

1. Measure the usable inside length and width of your rectangular planting bed. Exclude walls and separate access paths, then choose metres or feet.
2. Enter the centre-to-centre distance between plants in a row, in centimetres or inches. Get that distance from your seed packet, plant label or suitable local guidance.
3. If rows need a different distance, enable separate row spacing and enter it in the same spacing unit. Otherwise the calculator uses plant spacing in both directions.
4. Read the total and the rows-by-positions breakdown. Rows run along the entered length. Exchange length and width yourself to check the other orientation.

What you can calculate

• A whole-position count for one rectangular bed, with the number of rows and positions per row.
• Equal spacing in both directions or a separate between-row distance.
• Metres or feet for the bed and centimetres or inches for spacing, including mixed unit choices.
• An explained edge rule and a copyable summary of the inputs, layout and assumptions.

Useful for planning a planting bed

• Check how many planting positions a raised bed or other usable rectangular patch can hold at your chosen spacing.
• Compare the counts for two spacings or row directions without building a full garden plan.
• Plan rows with different within-row and between-row distances while keeping those measurements distinct.

Understanding plant spacing and the bed edges

Plant spacing is measured between plant centres, not from leaf to leaf or pot edge to pot edge. Within-row spacing runs along the bed length; between-row spacing runs across its width.

This calculator reserves a full rectangular cell for each position. A cell is one plant spacing long and one row spacing wide. It centres the resulting grid and keeps each outer plant centre at least half a spacing from the relevant bed edge.

For this full-cell convention, positions per row = floor(length ÷ plant spacing), rows = floor(width ÷ row spacing), and total = positions per row × rows. All distances are converted exactly to compatible units before dividing.

A density estimate based only on bed area does not check complete cells on each side. For example, a 1 m × 1 m bed at 30 cm spacing has 3 × 3 = 9 complete positions here, even though area divided by spacing area is about 11.11.

The count belongs to the entered row direction and this edge rule. It is not the largest possible count under every boundary policy, rotation or staggered layout. Another calculator can legitimately return a different number under different assumptions.

Plant count examples

Equal spacing: a 3 m × 1.2 m usable bed at 30 cm spacing gives 10 positions per row and 4 rows, for 40 positions.

Separate rows: the same 3 m × 1.2 m bed, with 30 cm within rows and 60 cm between rows, gives 10 × 2 = 20 positions.

Feet and inches: an 8 ft long × 4 ft wide bed with 12 in spacing in both directions gives 8 × 4 = 32 positions.

No complete cell: a 0.2 m × 1 m rectangle at 30 cm spacing has zero positions along its length, so the total is zero. The positive measurements are valid; the chosen full-cell layout simply does not fit.

What this layout count does not decide

It does not choose crop spacing or predict growth, survival, harvest or yield. Use guidance suited to the plant, variety and local conditions; the software input limits are not botanical advice.

Use only one clear rectangular planting space. Walls, obstacles and separate access paths are not modelled. Calculate disconnected rectangles separately rather than combining their areas into a pretend rectangle.

This tool does not model staggered or triangular arrangements, circles, irregular beds, mixed crops, recommended varieties or commercial planting rates.

Changing a unit reinterprets the number already typed; it does not convert the draft. Counts are rounded down separately on each axis, including valid zero results.

Your measurements and this calculation

The calculator works in the browser without an account, upload or calculation API. It does not save or send the measurements you enter.

Copy is optional and includes the current measurements and layout assumptions. This calculation-specific statement does not claim that the surrounding website has no analytics or other network traffic.