Seed packets give you row spacing for farm-style gardens with walking paths — almost useless for a 4×8 raised bed. Intensive beds use equidistant spacing instead: every plant the same distance from every neighbor, no wasted path space. This calculator counts exactly how many plants that means for your bed. Pick a crop — tomatoes at 24 inches, peppers at 18, carrots at 3 — or set a custom spacing, enter your bed size, and get the count, the row layout, and a number you can take straight to the seed rack.
Then it shows you the trick most gardeners never run the math on: triangular spacing. Offset every other row by half the spacing and the rows can sit 13% closer together (0.866 × spacing, the geometry of a hexagon) while every plant keeps full distance from all its neighbors. Same airflow, same root room, roughly 15% more plants in the same bed — for a 4×8 bed of lettuce, that’s typically 5–6 extra heads per planting. The calculator runs both layouts side by side for your exact dimensions so you can see precisely what the switch is worth. One honest warning baked in: space to the mature plant, not the transplant. The June garden is planted in May by people who believed the seedling.
Frequently Asked Questions
How do I calculate how many plants fit in a bed?
Convert your bed to inches and divide by the spacing: plants per row = bed length ÷ spacing, number of rows = bed width ÷ spacing, both rounded down, then multiply. A 96×48-inch (8×4 ft) bed at 12-inch spacing fits 8 × 4 = 32 plants in a square grid. Triangular offset rows squeeze the rows to 0.866 × spacing and usually fit about 15% more.
What is triangular plant spacing and why does it fit more plants?
In triangular (offset or staggered) spacing, every other row shifts sideways by half the spacing, so each plant sits in the gap of the neighboring row. Plants stay the same distance from all neighbors, but rows can move from 1.0 to 0.866 times the spacing apart — hexagonal close-packing. The result is roughly 15% more plants per bed with no loss of air circulation or root room.
How far apart should tomatoes be planted in a raised bed?
24 inches plant-to-plant for staked or caged indeterminate tomatoes in an intensive bed — an 8×4 ft bed fits 8 plants in a square grid. Unsupported sprawling plants need 36 inches or more. Closer than 24 inches forces heavy pruning and slows leaf drying, which invites early blight and septoria.
Why is intensive-bed spacing different from the seed packet?
Seed packets assume row gardening: tight spacing within a row, then an 18–36-inch walking path between rows. Raised and intensive beds have no internal paths — you work from the edges — so plants sit on an equidistant grid at the in-row distance in both directions. That is why a packet can say “thin to 3 inches, rows 18 inches apart” while an intensive bed grows the same carrots on a simple 3-inch grid.
Can I plant closer than the recommended spacing to get more harvest?
Usually it backfires. Crowded plants compete for light and nutrients, air movement drops, leaves stay wet longer, and fungal disease moves in — so total harvest per square foot often falls even though plant count rises. If you want more from the same bed, switch to triangular spacing (about 15% more plants at full distance) instead of shrinking the spacing itself.