Enter your hedge length, plant spacing and rows to see how many plants you need, with a spares allowance built in.
The formula
Plants per row = floor(length ÷ spacing) + 1, times the number of rows. A staggered double row uses the same count per row, offset by half a spacing, and knits into a thicker screen. The calculator adds a 10% spares figure because a few failures in year one are normal.
Worked example
A 50 ft run at 24 inch spacing: floor(600 ÷ 24) + 1 = 26 plants in a single row; order 29 with spares. As a double row, 52 plants.
Spacing by hedge type
Typical centres: formal clipped hedges 12–18 in for a dense wall, privacy screens of larger shrubs 24–36 in, and conifer screens 3–5 ft depending on species vigour. Tighter spacing closes the gaps sooner but costs more and increases competition later; wider spacing is cheaper and healthier long-term but takes an extra season or two to knit. Plant the row half a spacing inside your boundary so the mature hedge stays on your side.