Reforestation Seedlings Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/8/2026
The number of seedlings needed for reforestation is calculated with surface area (ha) × planting density (seedlings/ha). To reforest 1 hectare at a density of 2,000 seedlings/ha, you need 2,000 seedlings.
Explanation
Planting density (the number of seedlings installed per hectare) is the main factor determining the total number of seedlings needed for a reforestation project, well ahead of the area itself once that is fixed. Common densities vary greatly depending on the species and the goal pursued: broadleaf trees (oak, beech) are generally planted at 800 to 2,500 seedlings per hectare, while young conifer plantations (pine, spruce) can reach 4,000 seedlings per hectare, a higher density that promotes fast vertical growth and limits the development of low branches, at the cost of more frequent thinning later on. Forestry practices have also changed a lot: planting densities have steadily decreased over the past 50 years, in some cases going from 10,000 seedlings per hectare to 1,000 or fewer, a choice that reduces initial planting cost at the price of different individual growth. This purely geometric calculator always rounds the result up to the next whole seedling: an area of 2.3 hectares at a density of 1,800 seedlings/ha requires exactly 4,140 seedlings, not a fractional value. It is distinct from our carbon offset trees calculator, which answers a different question (how many trees to absorb a given amount of CO2), unrelated to ground planting density — and from our vegetable garden plant count calculator, which applies a two-dimensional grid (rows × columns) rather than an overall areal density, better suited to a garden than a forest plot.
Example: reforesting 1 hectare at 2,000 seedlings/ha
Inputs
Area: 1 hectare. Planting density: 2,000 seedlings/ha.
Calculation
Number of seedlings = 1 × 2,000 = 2,000.
Result
This reforestation requires 2,000 seedlings.
Frequently asked questions
What planting density should be chosen?
This depends on the species and the goal: broadleaf trees are generally planted at 800 to 2,500 seedlings/ha, young conifers up to 4,000/ha for fast vertical growth. A diversified ecological restoration goal often favors a lower density and a greater variety of species, while a timber production plantation aims for a higher density followed by regular thinning.
Why is the result always a whole number rounded up?
Because there is no such thing as a fraction of a seedling to order: a theoretical result of 4,139.9997 seedlings (due to a slight floating-point rounding gap) is rounded up to 4,140, the next whole number, never down to the lower whole number, which would leave part of the area unplanted.
Does this calculator account for seedling losses (mortality after planting)?
No, it only gives the number of seedlings to install for the targeted density, with no margin for the usual mortality rate after planting (which varies by species, climate, and maintenance, often around 10 to 20% in the first year). In practice, it is common to order a slightly higher number of seedlings than the result shown, to anticipate this replacement.