GardenCalcs.uk
Row Planting Calculator — Plants per Row
Calculate plant quantities for straight rows in beds and allotments.
Length of each row along the bed
How many parallel rows across the bed
Gap between plants within a row, e.g. 30 cm for cabbages
Gap between adjacent rows, centre to centre (allows weeding and harvesting)
Gap from bed edge to first plant
Extra plants for non-germination
Access path width between rows
How We Calculate This
Plants per row = Floor(Row Length ÷ Plant Spacing) + 1. The +1 is the plant at the far end of the row (fence-post rule).
Total plants = Plants per Row × Number of Rows.
Bed width = (Number of Rows − 1) × inter-row gap, where the gap is the larger of Row Spacing and any Path Width you enter (so a wide access path is honoured without double-counting clearance).
Bed area = Row Length × (Bed Width + one inter-row gap), leaving half a gap of margin beyond the outer rows on each side for plant spread and edge access.
Frequently Asked Questions
North-south orientation gives the most even sun distribution. In the UK, run rows along the longest dimension for efficiency.
Allow 30-45 cm for kneeling access and 60 cm for paths you walk along. Wheelbarrow paths need 90 cm minimum. If you enter a Path Width wider than your Row Spacing, the calculator uses the path width as the gap between those rows rather than adding it on top — row spacing already builds in some access room.
Usually yes. Row spacing accounts for root spread, air circulation, and access for weeding and harvesting.
Run rows north to south when possible so both sides get equal sunlight through the day. For sloping sites, run rows across the slope to reduce soil erosion from rain.
Divide the row length by the plant spacing, then add 1 for the end plant. For example, a 3m row at 30cm spacing: 3 / 0.3 + 1 = 11 plants per row.
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Last updated: February 2026
All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.