Tree Carbon Offset Calculator
How many trees does it take to absorb your CO₂ emissions? Based on ≈22 kg per mature tree per year.
Result
Mature trees needed
182
Years for a single tree
181.8
How it works
A mature tree absorbs roughly 22 kg of CO₂ per year — commonly cited figures range from about 21 to 25 kg depending on species, age, climate and soil. Divide your emissions by that rate and you get the number of trees needed to absorb them continuously. The numbers are humbling: offsetting 4 tonnes of annual emissions — a plausible personal footprint — takes around 182 mature trees working all year, every year. A single tree would need nearly two centuries to absorb what one year of such a footprint emits. That is exactly why offsetting complements but never replaces reduction. Young trees absorb little in their first decade, forests can burn or be cleared, and the CO₂ needs to stay stored for decades to matter. Plant trees, yes — but treat the reduction levers (transport, energy, diet) as the main event.
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Frequently asked questions
How much CO₂ does one tree absorb per year?
A mature tree absorbs roughly 21–25 kg of CO₂ per year; this calculator uses 22 kg. Young trees absorb far less during their first years of growth.
Is planting trees enough to offset my footprint?
No. Trees need decades to absorb meaningful amounts and the storage must last. Offsetting is a complement — cutting emissions at the source remains the priority.
Why do estimates of trees’ absorption vary so much?
Species, age, growth rate, climate and soil all matter. A fast-growing tropical tree and a slow northern conifer can differ several-fold in annual CO₂ uptake.
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