Plant Spacing Calculator

Find how many plants a bed needs from the area and the on-center spacing, for a square grid or a tighter triangular layout.

Planning estimate: this is a planning estimate. Coverage varies by product (bag size, compaction, waste, slope and how tightly you pack). Buy about 5–10% extra and confirm the coverage printed on the product before you order.

Calculator

sq ft
Total area to plant — use the lawn area tool for odd shapes.
ft
Center-to-center distance; space to the mature width.
Triangular staggered rows fit ~15% more plants.
Plants needed (square)100 plants
Square grid100 plants
Triangular / staggered115 plants
Spacing1.00 ft on center

At 1.00 ft on center over 100 sq ft you need about 100 plants (square layout). Triangular spacing packs ~15% more plants into the same bed; space to the mature width so they knit together without crowding.

Buying plants for a bed or a groundcover planting comes down to one question: how many fit at the spacing on the tag? Space them too far apart and the bed looks bare for years; too close and you waste money and invite crowding. This calculator turns your bed area and the recommended on-center spacing into a plant count for both a simple square grid and a tighter triangular (staggered) layout, which fits about 15% more plants into the same space and closes the gaps faster.

Formula

Each plant needs one “cell” of ground set by the spacing. A square grid uses a square cell; a triangular (staggered) layout packs the rows tighter:

square: plants = floor( area ÷ spacing² )
triangular: plants = floor( area ÷ (spacing² × 0.866) )

Spacing is measured on center — from the middle of one plant to the middle of the next. The 0.866 factor is why staggered rows fit about 15% more plants into the same bed.

Worked example

A 100 sq ft bed with plants 1 ft on center:

square: 100 ÷ 1² = 100 plants
triangular: 100 ÷ (1² × 0.866) = 115 plants

So the same bed holds about 100 plants on a square grid or 115 staggered. Wider spacing drops the count fast, because it is squared.

Spacing plants so they knit together

Good spacing lets each plant reach its mature size without crowding, while still filling in to a solid mass of foliage or groundcover. A few rules of thumb:

  • Space to the mature width. A groundcover that spreads to 12 in wide goes about 12 in on center; a shrub that reaches 4 ft goes about 4 ft on center.
  • Spacing is squared. Doubling the spacing quarters the plant count — small changes move the number a lot, so measure your spacing carefully.
  • Triangular for coverage. Staggered rows close the gaps and cover ground faster, fitting roughly 15% more plants; a square grid is easier to lay out and edge.
  • Round to whole flats. Plants sell in flats and pots, so round up and keep a few spares for gaps and losses.

Not sure of the bed area? Break an irregular shape into rectangles with the lawn area tool first, then bring the total here. Tighter spacing costs more up front but hides bare soil sooner.

Reference table

Plants per 100 sq ft of bed by on-center spacing (pure geometry — scale up for your own area):

Spacing on centerSquare gridTriangular
6 in400461
9 in177205
12 in100115
18 in4451
24 in2528
36 in1112

Frequently asked questions

How many plants do I need for a bed?
Divide the bed area by the spacing squared. A 100 sq ft bed at 1 ft on center holds about 100 plants on a square grid, or about 115 in a staggered triangular layout. Enter your area and spacing to get the number.
What does "on center" spacing mean?
It is the distance from the center of one plant to the center of the next, not the gap between their edges. Nurseries and plant tags give recommended spacing on center — match it to the plant’s mature width.
Square or triangular spacing — which should I use?
Triangular (staggered rows) fits about 15% more plants and covers bare ground faster, which is great for groundcovers and mass plantings. A square grid uses fewer plants and is simpler to lay out and maintain.
How far apart should I space groundcover?
Space to the plant’s mature spread so it fills in without crowding — often 8 to 18 in on center for common groundcovers. Closer spacing covers faster but costs more; check the tag for the recommended distance.

Related calculators

Mulch Ring VolumeCalculate mulch volume for a tree ring from the outer and inner radius and depth — cubic yards and 2 cu ft bags. Free calculator with formula and worked example.Lawn AreaLawn area calculator: break an irregular yard into up to three rectangles and add them up for total square footage to feed the seed, sod and fertilizer tools.