Home › Everyday Life › Plant Spacing Calculator

Plant Spacing Calculator

Computes how many plants fit in a rectangular bed from its length and width, the in-row spacing, the row spacing and the layout pattern (square grid or staggered triangular rows at 0.866 × row spacing), plus rows, plants per row and plants per square metre.

When to use

You are planting a bed, border, hedge, vegetable plot or ground cover at a given spacing and need the plant count or the density per square metre.

Do not use when: You are seeding a lawn by weight (use lawn-seed-fertilizer) or planting an irregular, non-rectangular area (split it into rectangles first).

Formula

square: plants_per_row = floor(L / s) (+1 without edge offset), rows = floor(W / r) (+1), plants = plants_per_row × rows; triangular: h = 0.866 × r, rows = floor(W / h) (+1), full rows floor(L / s) (+1) plants, offset rows floor(L / s − 0.5) (+1) plants, rows alternate starting with a full row; plants_per_m2 = plants / (L × W); density = 1 / (s × h)

Plants are placed on a grid whose first plant is half a spacing from the edge (or on the edge when edge_offset is false); the triangular pattern shifts every second row by half a spacing and brings rows to √3/2 = 0.866 of the spacing, giving 15.5 % more plants per area for the same distance between neighbours. Spacings should be the mature-spread distances given for the plant.

Inputs

Parameter	Type	Unit	Required	Description
`bed_length_m`	number	m	yes	Length of the bed (rows run along this side). Range: > 0, ≤ 10000
`bed_width_m`	number	m	yes	Width of the bed (rows are spaced across this side). Range: > 0, ≤ 10000
`plant_spacing_m`	number	m	yes	Distance between plants within a row. Range: > 0, ≤ 100
`row_spacing_m`	number	m	no	Distance between rows; defaults to plant_spacing_m. In the triangular pattern the rows are 0.866 × this value apart. Range: > 0, ≤ 100
`pattern`	enum: square \| triangular		default square	Square grid or staggered rows in which each plant sits between the two plants of the neighbouring row.
`edge_offset`	boolean		default true	true: the first plant sits half a spacing in from each edge (count = floor(length / spacing)); false: plants start on the edge (count = floor(length / spacing) + 1).

Outputs

Output	Type	Unit	Description
`plants_total`	integer		Total number of plants that fit.
`plants_per_row`	integer		Plants in a full row (first, third, fifth … row in the triangular pattern).
`plants_per_alternate_row`	integer		Plants in the offset rows of the triangular pattern (equal to plants_per_row for the square grid).
`rows`	integer		Number of rows across the bed width.
`row_spacing_m`	number	m	Distance between rows (row spacing × 0.866 for triangular).
`plants_per_m2`	number	plants/m²	plants_total / bed area.
`plants_per_m2_theoretical`	number	plants/m²	1 / (plant spacing × row spacing used), the density of an unbounded planting.
`spacing_cm`	number	cm	In-row spacing in centimetres.
`coverage_note`	string		Layout summary and comparison with the other pattern.

Example

10 × 2 m bed, 0.3 m square grid: {"bed_length_m":10,"bed_width_m":2,"plant_spacing_m":0.3,"pattern":"square"} → {"plants_total":198,"plants_per_row":33,"rows":6,"row_spacing_m":0.3,"plants_per_m2":9.9,"spacing_cm":30}

10 × 2 m bed, 0.3 m triangular: {"bed_length_m":10,"bed_width_m":2,"plant_spacing_m":0.3,"pattern":"triangular"} → {"plants_total":228,"plants_per_row":33,"plants_per_alternate_row":32,"rows":7,"row_spacing_m":0.26,"plants_per_m2":11.4}

GET https://tttkmbb.com/api/v1/calculate/plant-spacing?bed_length_m=10&bed_width_m=2&plant_spacing_m=0.3&pattern=square

Machine access

API: GET https://tttkmbb.com/api/v1/calculate/plant-spacing (query parameters) or POST with a JSON body {"inputs": {...}}
Schema: https://tttkmbb.com/api/v1/calculators/plant-spacing · Markdown: https://tttkmbb.com/everyday/plant-spacing.md · JSON definition: https://tttkmbb.com/everyday/plant-spacing.json
MCP: server https://tttkmbb.com/mcp, tool run_calculator with calculator_id="plant-spacing"
OpenAPI operationId: calculate_plant_spacing
Freshness: static. Authentication: none. Rate limit: fair use (see rate limits).

Sources

Circle packing – square versus hexagonal (triangular) arrangements (Wikipedia) (reference)

FAQ

Which spacing should I enter?

The distance between plant centres recommended for the mature plant (label or nursery data), which is usually its mature spread; using a smaller spacing gives quicker cover at higher cost.

Why does the triangular pattern fit more plants?

Staggering the rows lets them sit 0.866 × the spacing apart while every plant keeps the same distance to its six neighbours, the hexagonal (densest) packing of circles.

Does the count change if I start plants on the edge?

Yes: with edge_offset false one more plant fits per row and one more row fits, but plants on the edge overhang the bed once mature.

Related calculators

Lawn Seed and Fertilizer Calculator — Seed and fertilizer for lawn areas.
Area Converter — Convert the bed area between units.
Rectangle Calculator — Area and perimeter of the bed.