Donaldson R F Plant Spacing Calculator
Work out how many plants fit a bed or row, from its size and your plant and row spacing.
How it is worked out
This uses a simple grid model: plants per row = bed length ÷ spacing along the row, rows = bed width ÷ spacing between rows, and total plants = plants per row × rows (rounded down, since a part-plant doesn't fit). It's a straightforward area-division estimate, not a precise edge-to-edge fence-post count — real layouts often leave a small margin at the edges, and planting in a staggered (triangular) pattern instead of a square grid can fit noticeably more plants in the same space.
Source: standard grid/area-division arithmetic (length ÷ spacing × width ÷ row spacing), the common simple method used by seed and plant suppliers' spacing guides.
Working out fertiliser instead? Try the Fertiliser NPK Calculator.