Tree spacing is a design input, not a universal answer
A tree-spacing calculator can do the geometry accurately only after you choose an appropriate spacing. That choice can change with species, cultivar or rootstock, mature crown, woodland objective, machinery, access, orchard system and future management. This page therefore does not contain a fake universal species database.
Current UK sources illustrate the range. Woodland Trust woodland planning commonly refers to densities around 1,000–1,600 trees per hectare depending on the goal, and gives examples including 3m spacing at about 1,100 trees/ha, 2.5m at about 1,600, and 2m at 2,500. RHS fruit-tree guidance shows that planting distance changes materially with rootstock — exactly why “apple tree spacing” cannot be reduced to one number.
1 hectare = 10,000m². 1 acre ≈ 4,046.856m². At 2m × 2m rectangular spacing, each tree occupies 4m² theoretically, giving 2,500 trees/ha or about 1,011.71 trees/acre before margins and tracks.
Area density versus whole positions
The density mode answers a theoretical question: if the whole area were filled by the selected repeating geometry, what is the density? That is useful for comparing schemes and converting to trees per hectare or acre.
The rectangular-plot mode answers a different question. It applies the explicit boundary setback to all four sides and counts actual centre positions at the selected along-row and row spacing. This means the whole-position result can differ from simply multiplying area by density. The result also ignores access tracks, headlands, ponds, existing trees and other excluded ground unless you remove those from the plot dimensions first.
Square rows and equal triangular spacing
Rectangular rows use tree spacing × row spacing as the theoretical area per tree. Equal triangular spacing uses the geometric cell area s² × √3 ÷ 2, not an arbitrary “add 15%” rule. At the same equal centre-to-centre distance, triangular geometry has a higher theoretical density.
Worked examples
2,500 theoretical trees/ha; about 1,011.71 trees/acre.
10,000 ÷ 9 = about 1,111.11 theoretical trees/ha.
At 2m spacing and a 1m setback, positions run 1,3,…19m and 1,3,…9m: 10 × 5 = 50.
Real planted count falls when non-planting areas are removed from the geometry.
Keep tree, plant and hedge calculations separate
The Plant Spacing Calculator is for garden beds and smaller planting patterns. The Hedge Plant Calculator handles linear runs and single/double hedge rows. This page focuses on larger-area tree density, hectares/acres and explicit plot layouts.