Tree Carbon Sequestration Calculator
Estimate the total CO₂ sequestered by a grove of trees based on species, age, growing conditions, and a chosen time horizon. Useful for reforestation projects, carbon offset planning, and conservation reporting.
Last updated: September 2026
Formula below · 2 sources (climate.gov, Wikipedia) · Updated Sep 2026
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About this calculator
Trees sequester carbon by absorbing CO₂ during photosynthesis and storing carbon in their biomass — wood, roots, and leaves. The rate of sequestration is not linear; it follows a logarithmic growth curve because trees grow rapidly when young and slow as they mature. The formula used here is: CO₂ sequestered = numberOfTrees × (treeSpecies × ln(treeAge + timeHorizon) × growingConditions × 3.67), where treeSpecies is a species-specific biomass growth coefficient, ln is the natural logarithm, growingConditions is a multiplier reflecting soil quality and rainfall, and 3.67 converts carbon mass to CO₂ mass (the ratio of molecular weights: 44/12 ≈ 3.67). The species options set the coefficient (35 fast-growing, 42 medium, 48 slow-growing dense hardwoods), and optimal growing conditions (fertile soil, adequate rainfall) amplify it. Because the log term uses the tree's age at the end of the period (current age + time period), the result is the estimated total CO₂ stored in the trees by then, including what they stored before the period began; it is an illustrative curve, not a species-specific allometric model.
How to use
Assume you have 100 medium-growth trees (maple/birch, coefficient 42), currently 5 years old, in optimal growing conditions (1.3), over a 20-year horizon. Step 1 — log term: ln(5 + 20) = ln(25) ≈ 3.219. Step 2 — species coefficient: 42 × 3.219 = 135.2. Step 3 — growing conditions: 135.2 × 1.3 = 175.8. Step 4 — carbon to CO₂: 175.8 × 3.67 ≈ 645.1 lbs CO₂ per tree. Step 5 — 100 trees: about 64,510 lbs (29.3 metric tons) of CO₂ stored by the end of the 20 years.
Frequently asked questions
How much CO2 does a single tree absorb over its lifetime?
The amount varies enormously by species, climate, and growing conditions, but a typical mature temperate tree absorbs roughly 21–48 kg (about 48–100 lbs) of CO₂ per year. Over a 40-year lifespan, a single oak might sequester around 1–2 tonnes of CO₂ in its above-ground biomass. Fast-growing plantation species like eucalyptus or poplar can absorb significantly more in the same period. However, these figures represent gross sequestration — decomposition of leaf litter and soil respiration return some carbon to the atmosphere, so net figures are always lower.
Which tree species sequester the most carbon per tree?
Fast-growing species with high wood density and large final biomass tend to sequester the most carbon per tree. Tropical species like teak and mahogany, and temperate species like hybrid poplar, black walnut, and Douglas fir, are commonly cited as high-sequestration options. However, planting native species appropriate to your local climate and soil often produces better long-term results than exotic high-performers, because native trees support local biodiversity and are more resilient to local pests and drought. Carbon sequestration should also be balanced against considerations of water use, fire risk, and ecosystem fit.
How long does it take for newly planted trees to make a significant climate impact?
Newly planted trees sequester very little carbon in their first few years as they establish root systems and grow slowly. Meaningful carbon accumulation typically begins after 5–10 years, with sequestration rates peaking in middle age — roughly years 20–60 depending on species. This lag effect means that tree planting, while valuable, is not a short-term climate solution and must be accompanied by immediate emissions reductions. For carbon offset projects, permanence guarantees are also critical, as deforestation, disease, or wildfire can release stored carbon and negate the climate benefit.