Plant Spacing Calculator

Proper plant spacing is the difference between a thriving garden and a crowded, disease-prone one. This calculator tells you exactly how many plants you need to fill a garden bed based on the recommended spacing for your chosen plant. It supports both square and triangular (offset row) layouts — triangular spacing fits about 15% more plants in the same area and is ideal for dense groundcovers and ornamentals.

Enter Your Measurements

Bed Length (ft)(ft)

Bed Width (ft)(ft)

Plant Spacing (inches)(in)

Results

Plants Needed (Square Layout)

plants

Plants Needed (Triangular Layout)

plants

Total Bed Area

40.0

sq ft

Area per Plant

1.00

sq ft

Formula

Square: Plants = Area ÷ Spacing² | Triangular: Plants = Area ÷ (Spacing² × √3/2)

How to Use This Calculator

How to Use

1
Measure the length and width of your garden bed in feet.
2
Find the recommended spacing for your plant on its tag or seed packet.
3
Enter the spacing in inches (e.g., 18 inches for many perennials).
4
Compare square vs triangular layouts — triangular fits ~15% more plants.
5
Add 10–15% to your plant count for edge losses and transplant failures.

Frequently Asked Questions

What spacing should I use for common vegetables?

Common vegetable spacings: lettuce 6–8 in, carrots 3–4 in, tomatoes 18–24 in, peppers 12–18 in, cucumbers 12 in, zucchini 24–36 in, kale 12–18 in. Always check the seed packet for variety-specific recommendations, as compact and full-size varieties differ significantly.

When should I use triangular vs square spacing?

Triangular (offset row) spacing is ideal for groundcovers, ornamentals, and crops where maximum coverage matters, like strawberries or mass-planted perennials. Square spacing is easier to manage for vegetables and plants you'll be tending individually, since you can walk between rows more easily.

What happens if I plant too closely?

Crowded plants compete for water, nutrients, and light, leading to reduced yields, stunted growth, and increased humidity around foliage — which promotes fungal diseases like powdery mildew and botrytis. It's nearly always better to plant at the recommended spacing than to overplant.

Should I adjust spacing for raised beds vs in-ground planting?

Raised beds with loose, amended soil can sometimes support slightly tighter spacing since roots access nutrients more easily and drainage is better. However, the standard guidance is still to follow recommended spacings. Square-foot gardening methods (by Mel Bartholomew) use specific per-plant counts per square foot for raised beds.

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About This Calculator

This calculator uses the formula: Square: Plants = Area ÷ Spacing² | Triangular: Plants = Area ÷ (Spacing² × √3/2). All calculations follow industry-standard methods. Results are estimates — always verify with a licensed professional for structural or code-compliant work.

Built and maintained by the CalcSmart team. Last updated March 2026.

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