Calculator

Square Foot Garden Calculator Plants per Square & Garden Kits

Enter your bed size and pick a crop or a themed garden kit to get how many plants to buy and how much soil to fill the bed.

Your project

ft
ft
in
Result
Enter your measurements above and click Calculate.

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How it works

squares = length × width; plants = squares × plants-per-square; themes allocate squares per crop

Plants per square foot

Plants per square foot
Plants / sq ftCrops
1Tomato, pepper, broccoli, cabbage, kale
4Lettuce, basil, parsley, swiss chard
9Spinach, onion, cilantro, beet, bush bean
16Carrot, radish, chives

A 4×4 bed is 16 one-foot squares. A 4×8 bed is 32. Multiply the per-square count by your number of squares: e.g. 16 squares of lettuce = 64 plants.

Frequently asked questions

How many plants fit in a 4x4 raised bed?
A 4×4 bed has 16 one-foot squares. It depends on the crop: 16 tomatoes or peppers (1 per square), 64 lettuce (4 per square), 144 spinach or onions (9 per square), or 256 carrots/radishes (16 per square). Most people mix crops.
What plants go in a salsa garden?
A classic 4×4 salsa garden holds about 4 tomatoes, 4 peppers, 36 onions, and 36 cilantro plants. Add a tomatillo if you like a green salsa — tomatillos need two plants to pollinate.
How much soil do I need for a square foot garden?
Multiply length × width × depth. A 4×4 bed filled 6 inches deep needs 8 cubic feet of soil — about 6 of the 1.5 cu ft bags. The classic Mel's Mix is equal parts compost, peat/coir, and vermiculite.

Estimates are guidance only — material quantities vary by project conditions. Always confirm with a professional before purchasing.