What is the difference between row spacing and plant spacing?

Plant spacing (in-row spacing) is the distance between plants along one row. Row spacing is the distance from one row to the next, often wider to leave room to walk or hoe. A packet that says thin to 12 in, rows 18 in apart means 12 in Plant Spacing and 18 in Row Spacing.

Does staggered planting always fit more plants?

No. It gains only when the closer row pitch fits an extra row. In a 10 × 4 ft bed at 12 in plants, 18 in rows go from 20 plants to 29, but 24 in rows go from 20 to 19, because both patterns fit 2 rows and the offset row loses a plant.

How many plants fit in a 4 x 8 raised bed?

Entered as 8 ft long and 4 ft wide: at 12 in both ways, 32 on a square grid and 30 staggered. At 12 in plants and 18 in rows, 16 square and 23 staggered.

Does it tell me how many seeds to buy?

Yes. Seeds to sow is plants × seeds per spot, and packets is that divided by the packet size, rounded up. A spot stays empty only if every seed in it fails, a chance of (1 − germination) to the power of the seeds per spot. At 80% germination, 20 spots sown 2 seeds each need 40 seeds, or 2 packets of 25, and about 19 of the 20 spots (96%) come up; with 1 seed a spot it is 16.

Why does a small bed still show 1 row?

Each count is rounded down but never shown below 1. A 1 ft wide bed with 18 in rows has no room for a full row spacing, and the tool still reports 1 row.

What if my crop uses the same spacing in every direction?

Type the same number in both fields. The Plant Spacing Calculator on this site takes a single spacing and also counts plants set right on the bed edges.

Seed Spacing Garden Planner

Plants per row, number of rows and total plants for a garden bed, from its length and width in feet and the row and in-row spacing on the seed packet. How it works

Garden length

Garden width

Crop

Pick a crop to fill in both spacings, or keep Custom and type your own.

Row spacing

Plant spacing

Planting Pattern

Standard rows and columns with equal spacing in all directions.

Seeds to buy

Seeds per spot

Germination

Percent of seeds that sprout, printed on the packet.

Seeds per packet

Optional: gives the packets to buy.

Total plants

Per row 10 · Rows 2

Layout

Plants / Row: 10
Rows: 2
Area (sq ft): 40

Seeds

Seeds to sow: 20 seeds
Spots expected to come up: 20 of 20 (100.0%)

Each seed is taken to come up on its own at the packet's germination rate, so a spot sown with n seeds stays empty with chance (1 - germination)^n. Thin extra seedlings to one per spot.

Bed to scale

10 ft long by 4 ft wide, one dot per plant.

About the Seed Spacing Garden Planner

A 10 × 4 ft bed planted 12 in apart in rows 18 in apart holds 2 rows of 10, or 20 plants. Staggering the rows fits a third row and gives 29. This seed spacing planner takes the bed’s length and width in feet and two spacings in inches, between plants in a row and between rows, and counts plants per row, rows and total plants for square or staggered planting. Pick one of 20 vegetables to fill in both spacings from the University of Illinois Extension table, and the bed is drawn to scale.

A 10 × 4 ft bed by plant and row spacing

Plant spacing	Row spacing	Square: rows × plants	Square total	Staggered total
6 in	12 in	4 × 20	80	78
6 in	18 in	2 × 20	40	59
12 in	12 in	4 × 10	40	38
12 in	18 in	2 × 10	20	29
12 in	24 in	2 × 10	20	19
12 in	36 in	1 × 10	10	10
18 in	18 in	2 × 6	12	18
24 in	36 in	1 × 5	5	5

Length 10 ft, width 4 ft. Staggered rows are 0.866 of the row spacing apart, and every second row starts half a plant spacing in.

A 20 × 10 ft row garden at wider spacings

Plant spacing	Row spacing	Square total	Staggered total
12 in	30 in	80	78
18 in	30 in	52	50
18 in	36 in	39	38

Length 20 ft, width 10 ft. When the narrower row pitch does not add a row, staggering only costs the plant each offset row loses.

Vegetable spacing the Crop list fills in

Crop	Between plants in a row	Between rows	Filled in (plants / rows)	Plants in an 8 × 4 ft bed, square grid
Beet	2 to 4 in	12 to 18 in	3 in / 15 in	96
Broccoli	18 to 24 in	30 to 36 in	21 in / 33 in	4
Cabbage	9 to 18 in	18 to 30 in	14 in / 24 in	12
Carrot	1 to 3 in	12 to 18 in	2 in / 15 in	144
Cauliflower	18 to 24 in	24 to 36 in	21 in / 30 in	4
Chard	4 to 8 in	18 to 24 in	6 in / 21 in	32
Sweet corn	9 to 12 in	24 to 48 in	11 in / 36 in	8
Cucumber	12 in	48 to 72 in	12 in / 60 in	8
Eggplant	18 to 24 in	30 to 36 in	21 in / 33 in	4
Garlic (from cloves)	3 in	12 to 18 in	3 in / 15 in	96
Kale	8 to 12 in	18 to 24 in	10 in / 21 in	18
Kohlrabi	3 to 6 in	18 to 24 in	5 in / 21 in	38
Lettuce (leaf)	2 to 4 in	12 to 18 in	3 in / 15 in	96
Onion (from plants or sets)	1 to 4 in	12 to 18 in	3 in / 15 in	96
Pepper	18 to 24 in	18 to 24 in	21 in / 21 in	8
Potato	10 to 12 in	24 to 36 in	11 in / 30 in	8
Radish (spring)	1 in	12 to 18 in	1 in / 15 in	288
Spinach	2 to 4 in	12 to 18 in	3 in / 15 in	96
Summer squash	18 to 24 in	36 to 48 in	21 in / 42 in	4
Tomato	18 to 36 in	36 to 60 in	27 in / 48 in	3

Ranges from “Recommended Spacing for Vegetable Planting”, University of Illinois Extension, as reprinted by the Master Gardeners of Northern Virginia. The Crop list fills in the middle of each range, rounded to whole inches. For sweet corn, cucumber and summer squash the table also gives hill planting (3 plants per hill); the list uses the single-plant spacing.

How to use this tool

Enter the bed length and width in feet. Rows run along the length.
Enter the row spacing and the plant (in-row) spacing in inches from the seed packet or plant tag, or pick a crop to fill both in.
Choose Square Grid or Staggered / Triangular.
Read Total Plants, Plants / Row (with the count for offset rows when it differs) and Rows.
Under Seeds to buy, set Seeds per spot (1 to 10), the Germination from the packet (1 to 100%) and, if you like, Seeds per packet, to get the seeds to sow, the spots likely to come up and the packets to buy.

Frequently asked questions

What is the difference between row spacing and plant spacing?: Plant spacing (in-row spacing) is the distance between plants along one row. Row spacing is the distance from one row to the next, often wider to leave room to walk or hoe. A packet that says thin to 12 in, rows 18 in apart means 12 in Plant Spacing and 18 in Row Spacing.
Does staggered planting always fit more plants?: No. It gains only when the closer row pitch fits an extra row. In a 10 × 4 ft bed at 12 in plants, 18 in rows go from 20 plants to 29, but 24 in rows go from 20 to 19, because both patterns fit 2 rows and the offset row loses a plant.
How many plants fit in a 4 x 8 raised bed?: Entered as 8 ft long and 4 ft wide: at 12 in both ways, 32 on a square grid and 30 staggered. At 12 in plants and 18 in rows, 16 square and 23 staggered.
Does it tell me how many seeds to buy?: Yes. Seeds to sow is plants × seeds per spot, and packets is that divided by the packet size, rounded up. A spot stays empty only if every seed in it fails, a chance of (1 − germination) to the power of the seeds per spot. At 80% germination, 20 spots sown 2 seeds each need 40 seeds, or 2 packets of 25, and about 19 of the 20 spots (96%) come up; with 1 seed a spot it is 16.
Why does a small bed still show 1 row?: Each count is rounded down but never shown below 1. A 1 ft wide bed with 18 in rows has no room for a full row spacing, and the tool still reports 1 row.
What if my crop uses the same spacing in every direction?: Type the same number in both fields. The Plant Spacing Calculator on this site takes a single spacing and also counts plants set right on the bed edges.

Important limitations

The bed is one rectangle with no paths or borders: take those off the length and width first. The bed can be 1 to 500 ft each way and the spacings 1 to 120 in; an empty or out-of-range field shows a message and no result. The Crop list covers 20 vegetables and uses the middle of each range; for other crops, hill planting or a variety with its own spacing, type the figures from the packet or tag. The drawing shows the first 2,000 plants of a bigger planting; the counts cover the whole bed. The seed figures take each seed to sprout independently at the packet’s germination rate; cold soil, old seed or pests can lower it.

Sources

Last reviewed: 2026-10-23

Using the two spacings on a seed packet

Seed packets give two spacings: between plants in a row and between rows, such as 12 in and 18 in. Type them in, or pick one of 20 vegetables under Crop to fill in the middle of the University of Illinois Extension range, such as tomatoes 27 in apart in rows 48 in apart, or carrots 2 in apart in rows 15 in apart. Rows run along the length, and the bed is drawn to scale, one dot per plant.

Which side is the length matters: a 10 × 4 ft bed at 12 in plants and 18 in rows gives 2 rows of 10, 20 plants; typed as 4 × 10 ft it gives 6 rows of 4, 24 plants. The Seeds to buy panel turns spots into seeds: 20 spots sown 2 seeds each is 40 seeds, or 2 packets of 25.

The spacing rule

plants per row = floor(length × 12 ÷ plant spacing)

rows = floor(width × 12 ÷ row spacing)

total = plants per row × rows for a square grid

For staggered planting the rows sit row spacing × 0.866 apart, so rows = floor(width × 12 ÷ (row spacing × 0.866)). Every second row is shifted half a plant spacing and holds floor((length × 12 − plant spacing ÷ 2) ÷ plant spacing) plants. The 0.866 is √3 ÷ 2, a true triangular grid when both spacings are equal.

Counts round down, never below 1. Seeds: seeds = plants × seeds per spot, packets = ceil(seeds ÷ packet size), and a spot stays empty with chance (1 − germination)ⁿ for n seeds, each seed sprouting independently. At 80% germination and 2 seeds a spot, 96% of spots come up: 19 of 20. The form is saved in this browser; Clear Saved Values resets it.

Fun Fact: In 1773 Joseph-Louis Lagrange proved that the hexagonal arrangement, the one staggered rows approximate, is the densest way to pack equal circles in a lattice, covering about 90.7% of the plane.

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Seed Spacing Garden Planner

Use the Seed Spacing Garden Planner

Layout

Seeds

Bed to scale

About the Seed Spacing Garden Planner

A 10 × 4 ft bed by plant and row spacing

A 20 × 10 ft row garden at wider spacings

Vegetable spacing the Crop list fills in

How to use this tool

Frequently asked questions

Using the two spacings on a seed packet

The spacing rule

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