Tree Planting Offset Calculator Formula

Understand the math behind the tree planting offset calculator. Each variable explained with a worked example.

Formulas Used

Trees Needed

trees_out = trees_needed

Total Planting Cost

total_cost = trees_needed * tree_cost

Cost per Ton Offset

cost_per_ton = trees_needed * tree_cost / co2_tons

Variables

VariableDescriptionDefault
co2_tonsAnnual CO2 to Offset(metric tons)10
kg_per_tree_per_yearCO2 Absorbed per Tree per Year(kg)22
tree_costCost per Tree Planted(USD)3
co2_kgDerived value= co2_tons * 1000calculated
trees_neededDerived value= ceil(co2_kg / kg_per_tree_per_year)calculated

How It Works

How to Calculate Trees Needed to Offset CO2

Trees absorb CO2 through photosynthesis and store carbon in their biomass.

Average Sequestration

A mature tree absorbs roughly 22 kg (48 lbs) of CO2 per year, though this varies widely by species, age, and climate.

Formula

Trees Needed = (CO2 in metric tons * 1,000) / kg absorbed per tree per year

Note that young trees absorb less; it takes 5-10 years for a sapling to reach average absorption rates.

Worked Example

Offset 10 metric tons of CO2 per year with trees absorbing 22 kg each at $3 per tree.

co2_tons = 10kg_per_tree_per_year = 22tree_cost = 3
  1. 01CO2 in kg: 10 * 1,000 = 10,000 kg
  2. 02Trees needed: ceil(10,000 / 22) = 455 trees
  3. 03Total cost: 455 * $3 = $1,365
  4. 04Cost per ton: $1,365 / 10 = $136.50/ton

Ready to run the numbers?

Open Tree Planting Offset Calculator