A Free Tool · Square Grid & Triangular Offset · Any Bed Size
How many plants fit in your garden bed?
Enter your bed length, width, and the spacing from the seed packet or plant tag, then
choose square-grid or triangular offset planting. You'll see the plant count, rows
× columns, and how much area each plant gets — useful before you buy transplants
or plan a new raised bed.
Square grid & triangular offset·Rows × columns & area per plant·Any bed size
Read this first
These are geometric maximums based on your bed dimensions and spacing — not a guarantee
of plant health or yield. The right spacing is the one on your seed packet or plant tag,
which reflects the plant's mature size. Crowding plants closer than recommended reduces
airflow, encourages disease, and usually cuts yields. The triangular layout fits roughly
15% more plants than a square grid at the same spacing distance — useful for dense
plantings of greens and herbs, but not every bed shape benefits equally.
Enter your bed dimensions in feet, the spacing between plants in inches, and choose a layout. The calculator shows how many plants fit, the row × column breakdown, and the area each plant gets.
Use the spacing on the seed packet or plant tag — center-to-center between plants.
Layout
Columns × rows
Area per plant
Total bed area
The math, honestly
How the plant count is figured
Both layouts start by converting your bed dimensions to inches:
L_in = length_ft × 12 and W_in = width_ft × 12.
Square grid: divide each dimension by the spacing and take the floor
to get whole columns and rows.
cols = ⌊L_in / spacing⌋,
rows = ⌊W_in / spacing⌋,
plants = cols × rows.
Example with defaults — a 10×10 ft bed at 12-inch spacing:
⌊120/12⌋ = 10 columns,
⌊120/12⌋ = 10 rows,
100 plants.
Each plant gets 12 × 12 = 144 in² = 1 sq ft.
Triangular offset: alternating rows are staggered by half a spacing
interval. The row-to-row distance shrinks to
spacing × √3/2 ≈ spacing × 0.866.
Because the packing is two-dimensional, the total is computed from the bed area:
plants = ⌊(L_in × W_in) / (spacing² × 0.866)⌋.
Same defaults: ⌊14400 / (144 × 0.866)⌋ = ⌊14400 / 124.7⌋ = 115 plants
— about 15% more than the square grid.
Why approximate: these formulas give the geometric maximum.
Edge effects, bed shape, and how you handle the offset rows in the last row can add
or subtract a plant or two. Treat the result as a planning number, not a count you
can hold anyone to.
Plant spacing quick reference
Common vegetable and herb spacings from seed-packet recommendations. Plant count is
for a single 4×8 ft bed in a square grid, computed with the same formula the
calculator uses. Triangular layout fits roughly 15% more.
Plant
Spacinginches, center-to-center
Cols × rows4 × 8 ft bed
Plants (square grid)4 × 8 ft bed
Loose-leaf lettuce
6
8 × 16
128
Spinach / arugula
6
8 × 16
128
Basil
8
6 × 12
72
Green onion
3
16 × 32
512
Radish
3
16 × 32
512
Beet / turnip
4
12 × 24
288
Carrot
3
16 × 32
512
Pepper
18
2 × 5
10
Tomato (bush)
24
2 × 4
8
Zucchini / squash
36
1 × 2
2
Cols = ⌊48 / spacing⌋; rows = ⌊96 / spacing⌋; plants = cols × rows.
Spacings reflect typical seed-packet minimums for full-size plants harvested at maturity.
Dense-harvest crops (cut-and-come-again greens, baby carrots) can be spaced closer;
always defer to the recommendation on your specific seed packet.
Reading the result well
A plant count is useful only if you act on it sensibly. Four things worth knowing before
you plant.
Spacing should match mature size, not seedling size
The spacing on the seed packet is for the plant at full size, not when you set out transplants. Seedlings look lost at 18 inches apart; they won't at harvest time. Planting to the packet spacing and thinning early if things crowd is better than planting dense and competing for light and water all season.
Triangular layout gains more in square beds than long narrow ones
The area-based formula for triangular offset distributes the ~15% gain evenly across the bed. In a very narrow bed (say, 2 ft wide with 12-inch spacing), you may only get one extra plant from the offset because there isn't room for a full staggered row. The square-grid formula is more predictable in narrow beds; use the triangular gain as a planning estimate, not a guarantee.
The count is a planning number, not a purchase order
Geometric plant count tells you the maximum. Buy a few extra transplants to account for seedlings that don't establish, gaps left by thinning, and the occasional slug. A 10% buffer is a reasonable planning cushion for most beds.
Companion planting breaks the grid
If you're interplanting crops (fast greens between slow tomatoes, for example), the calculator gives you a single-crop baseline. Mixed planting uses the space differently and often more efficiently than any single-crop grid. Use the calculator to understand how much room each crop needs, then plan the layout manually.
Plant spacing glossary
The terms behind the calculator, in plain English. Background definitions for home
gardeners, not agronomic specifications.
Plant spacing
The center-to-center distance between plants, measured in inches. It reflects the plant's mature spread and is the number on the seed packet or plant tag. Spacing determines both how many plants fit and how much root space, light, and airflow each plant gets.
Square grid
A planting pattern where every plant sits at the intersection of a regular grid: plants in each row are directly across from plants in the adjacent rows. It's the simplest layout and easy to manage, but it uses the available area slightly less efficiently than a triangular offset.
Triangular offset
Also called diamond or hexagonal spacing. Alternating rows are staggered by half the spacing interval so each plant nestles between two plants in the row above. The result is a denser pack — roughly 15% more plants than a square grid at the same spacing — because the row-to-row distance shrinks to spacing × 0.866 (√3/2).
Row spacing
In a triangular layout, the perpendicular distance between rows is not the same as the between-plant spacing. It equals spacing × √3/2 ≈ spacing × 0.866. For 12-inch plant spacing, rows are about 10.4 inches apart. The calculator uses this internally to estimate row count.
Area per plant
The square footage (or square inches) each plant is allocated. In a square grid this is simply spacing² — a 12-inch spacing gives each plant 144 in² = 1 sq ft. In a triangular layout it's spacing² × 0.866 ≈ 124.7 in² per plant at 12-inch spacing, which is why more plants fit.
Thinning
Removing weaker seedlings to give the survivors the spacing they need to reach full size. Direct-sown crops (carrots, beets, spinach) are typically sown denser than final spacing and thinned in stages. The plant count from this calculator assumes plants are already at final spacing, not seeding density.
Frequently asked
A 4 ft × 8 ft bed at 12-inch spacing in a square grid: cols = ⌊48/12⌋ = 4, rows = ⌊96/12⌋ = 8, total = 32 plants. In a triangular offset layout: ⌊(48 × 96) / (144 × 0.866)⌋ = ⌊4608 / 124.7⌋ = 36 plants. Each plant gets 1 sq ft in the square grid. Use the calculator above for any combination of bed size and spacing.
Triangular (also called offset or diamond) spacing staggers alternating rows by half the spacing interval, so each plant nestles into the gap between two plants in the row above. This is more efficient than a square grid because the row-to-row distance shrinks to spacing × 0.866 (√3/2). The result is roughly 15% more plants in the same area at the same plant-to-plant distance — which is why it's popular for dense crops like lettuce and herbs.
Check the seed packet or the plastic tag that comes with a transplant. The recommendation reflects the plant's mature size and is almost always given as center-to-center inches. When a range is given (e.g. 6–12 inches), use the smaller end for crops you harvest young or repeatedly (cut-and-come-again greens), and the larger end for plants you grow to full size. Never crowd plants tighter than the recommendation expecting them to compensate — reduced airflow and light usually hurt more than the extra plants help.
Tomatoes typically need 18 to 24 inches. At 24-inch spacing: cols = ⌊48/24⌋ = 2, rows = ⌊96/24⌋ = 4, total = 8 plants. At 18-inch spacing: cols = ⌊48/18⌋ = 2, rows = ⌊96/18⌋ = 5, total = 10 plants. In practice, many gardeners plant only 2–4 tomatoes per 4×8 bed and give them room to trellis or sprawl; the calculator gives the geometric maximum, but variety and training system matter too.
The calculator places the first plant at zero offset from the edge, giving the geometric maximum count. Some gardeners set the first plant half the spacing distance in from the edge so every plant — including edge plants — has the same amount of space in all directions. That approach reduces the count by roughly one column and one row. The calculator gives the upper-bound number; subtract one row and one column from the square-grid result if you prefer a half-spacing inset.
Loose-leaf lettuce can be grown as close as 4–6 inches for cut-and-come-again harvesting, or at 8–12 inches for full heads. Spinach, arugula, and most greens work well at 6 inches for leaf harvests or 10–12 inches for full plants. At 6-inch spacing in a 4×4 bed, a square grid gives ⌊48/6⌋ × ⌊48/6⌋ = 8 × 8 = 64 plants; triangular offset gives approximately 74. See the spacing reference table above for more examples.
Common mistakes
Plant count is straightforward geometry, but these four mistakes consistently produce a
bed that's over-planted, under-planted, or laid out differently than planned.
Spacing to seedling size instead of mature size
Transplants look lost at 18-inch spacing when first set out, which tempts gardeners to plant closer. But the spacing recommendation on a seed packet or plant tag reflects the plant at full size. Crowding to seedling size means plants compete for light and water all season — the problem the spacing recommendation was specifically meant to prevent. Calculate to the packet recommendation and resist tightening it because seedlings look small.
Buying the exact calculated count with no buffer
The calculator gives the geometric maximum — the most plants that fit given the bed dimensions and spacing. In practice, some transplants fail to establish, and a row that comes out slightly off can leave a gap. Buying the exact count with no margin means a run back to the nursery mid-planting. A 10% buffer — one or two extras for a typical bed — is straightforward insurance without significant extra cost.
Applying the triangular-offset count as if it's an exact row-by-row tally
The triangular-offset count is calculated from total bed area (using the 0.866 row-compression factor for equilateral packing), not from counting exact rows and columns — because row widths vary in a staggered layout. In a narrow bed or one where the spacing doesn't divide evenly into the bed dimensions, the actual count after laying out the grid by hand may differ by one or two plants from the calculator's estimate. Use it as a planning figure, not a purchase guarantee.
Forgetting that the count assumes a zero-inset from the bed edge
The calculator places the first plant at the edge with no margin — giving the upper-bound count. Many gardeners prefer to inset the first plant half the spacing distance from each edge, so every plant has equal room in all directions. That approach reduces the count by roughly one row and one column. If you prefer a half-spacing inset at the edges, reduce the calculator's result by one row and one column accordingly.