Plant Spacing Calculator

How to use

1. 1Pick a mode: How many plants fit in my bed, How big a bed I need, or Square foot gardening.
2. 2Pick your units (imperial or metric). The page converts values you already entered when you switch.
3. 3Pick a plant from the preset menu (tomato, pepper, lettuce, carrot, basil, strawberry, and 40+ more) to load the recommended spacing, or set custom spacing values.
4. 4Choose a row layout: rectangular grid or triangular (staggered). Triangular fits about 15 percent more plants when in-row and between-row spacing match.
5. 5Enter the bed length and width (or the plant count for the inverse mode), and read the result: total plants, rows, area per plant, density per square foot and per square meter.
6. 6For square foot gardening, pick 1, 4, 9, or 16 plants per square (tomato, lettuce, beet, carrot patterns) and switch between Bed size to plants and Plants to bed size.
7. 7Use Copy summary for a plain-text report you can paste into garden notes or a seed order.

About this tool

Plant Spacing Calculator turns a garden bed dimension and a per-plant spacing into a real plant count, or solves the inverse problem (how many plants you need to fill an area). Three modes share one engine. How many plants fit in my bed accepts the bed length and width plus the in-row and between-row spacing, then returns the plants per row, the number of rows, the total plants, the area per plant, and the planting density in plants per square meter and plants per square foot. The math is the standard plants-along-a-line formula floor(length / spacing) + 1 applied to both directions, with the option of a triangular (staggered, offset) row layout where alternating rows are shifted by half the in-row spacing. Triangular packing fits about 15 percent more plants for the same in-row spacing because each plant gets an equilateral-triangle area s squared times sqrt(3) divided by 2 instead of s squared. How big a bed I need accepts the plant count and the spacing, and returns the bed area required, a suggested square bed side length, and (when you fix a row length such as the 12-foot run you already have) the number of rows you need. Square foot gardening is a dedicated mode based on the 1, 4, 9, and 16 plants per square foot grid popularized by Mel Bartholomew: pick the number of plants per square (the 1, 4, 9, 16 ladder maps to 12, 6, 4, and 3 inch spacing respectively) and either compute the plant total from a bed size or the bed size from a plant total. A built-in plant preset library covers more than 50 common vegetables, herbs, fruits, flowers, and landscape plants (tomato determinate and indeterminate, pepper, eggplant, lettuce head and leaf, spinach, kale, broccoli, cabbage, cauliflower, carrot, radish, beet, onion, garlic, leek, potato, bean bush and pole, pea, sweet corn, cucumber, zucchini, winter squash, pumpkin, watermelon, melon, asparagus, okra, swiss chard, brussels sprouts, basil, parsley, cilantro, dill, thyme, oregano, rosemary, sage, mint, chives, strawberry, raspberry, blueberry, blackberry, marigold, zinnia, sunflower, cosmos, dahlia, lavender, hosta, boxwood) with recommended in-row and between-row spacing drawn from widely cited cooperative extension and seed company guidance. All inputs accept imperial (feet for bed dimensions, inches for spacing) or metric (meters for bed dimensions, centimeters for spacing) units, with a one-click switch that converts the values you already typed so the math stays consistent. A Copy summary button returns a plain-text report with the mode, bed size, spacing, layout, plant count, and density for pasting into garden notes, a seed order, or a project plan. Useful for backyard gardeners planning a season, homesteaders sizing a kitchen garden, raised bed builders deciding the bed dimensions before they cut lumber, market growers estimating transplant counts, landscape designers planting ground cover or a hedge, ag students working through planting density homework, and anyone who has stared at a packet of seeds wondering how many plants will actually fit. Spacing recommendations are general defaults; adjust to your variety, climate, and soil. Everything runs in your browser. No bed plan, plant list, or measurement is uploaded.

Free to use. Works in your browser. No signup, no login.