Tree Carbon Offset Calculator
How many trees does it take to offset your carbon footprint? According to the Arbor Day Foundation and USDA, a mature tree absorbs about 22 kg (48 lbs) of CO2 per year. This calculator helps you understand the tree-planting equivalent of your emissions, whether from flights, driving, or your annual carbon footprint. Note that carbon offsets are a supplement to, not replacement for, reducing emissions.
How We Calculate This
Trees needed = emissions_kg / (absorption_rate × time_horizon). Based on Arbor Day Foundation/USDA data: mature trees absorb ~48 lbs (22 kg) CO2 per year. Round up to ensure full offset.
Frequently Asked Questions
How much CO2 does a tree absorb?
A mature tree absorbs about 22 kg (48 lbs) of CO2 per year on average. This varies widely by species, age, and climate - from 10 kg for small trees to 50+ kg for large, fast-growing species.
Why is the time horizon important?
Trees take years to grow and absorb carbon. A 20-year horizon means each tree absorbs 440 kg total. A 10-year horizon halves this, requiring twice as many trees for the same offset.
Do carbon offsets actually work?
Tree planting can sequester carbon, but effectiveness varies. Concerns include: permanence (trees can burn or be cut), additionality (would trees exist anyway?), and timing (emissions happen now, absorption takes decades).
What about young vs mature trees?
Young trees absorb less CO2 initially but grow faster. Mature trees store more carbon but grow slowly. The 22 kg/year figure is a lifecycle average, but actual rates vary by age.
Related Calculators
You might also find these calculators helpful: Flight Carbon Footprint Calculator, and Ecological Footprint Calculator.
Tree absorption rates vary widely by species, age, climate, and growing conditions. This calculator provides rough estimates for awareness. Real carbon offset programs require verification and monitoring.