Tree Carbon Sequestration Calculator
Estimate carbon sequestered by trees from species, size, and age.
Calculate CO2 offset, carbon credits, and the environmental value of trees and forests.
How Trees Sequester Carbon Trees absorb CO₂ from the atmosphere through photosynthesis. The carbon is stored in wood, bark, leaves, roots, and soil organic matter. About 50% of dry wood biomass is carbon. CO₂ sequestered = Carbon stored × 44/12 (molecular weight ratio CO₂/C = 3.67)
USDA Forest Service Method (Urban Trees) Carbon stored (kg) = 0.25 × dry weight of above-ground biomass (kg) Biomass = species-specific allometric equations using diameter at breast height (DBH) Simplified: Carbon (kg) ≈ 0.25 × (0.15 × DBH²·²) for broadleaf trees (DBH in cm) Annual sequestration ≈ 22 kg CO₂/year for a medium mature tree (USDA estimate) Urban tree: 10–150 kg CO₂/year | Forest tree: 5–100 kg CO₂/year
Carbon or CO₂? The single most common mistake on this topic Read the units on every figure you meet, including the ones on this page. The two USDA lines just above are in CO₂. The species table further down, and the menu in the calculator, are in carbon. They differ by a factor of 3.667, because a carbon atom picks up two oxygen atoms on its way into the air. Get them the wrong way round and your answer is out by nearly 4x.
That USDA figure of 22 kg a year is the one that catches people, because 22 also happens to sit inside the plausible range for kg of carbon. It is CO₂. In carbon terms a mature urban shade tree runs about 6 kg a year, which is why the slow-growth class in the menu is the honest place to put a street tree, not the fast one.
Carbon Credit Value 1 carbon credit = 1 tonne CO₂ equivalent (tCO₂e). Voluntary carbon markets: $10–50 USD per tonne CO₂ (as of 2024). EU Emissions Trading System: ~$60–80 per tonne. Social cost of carbon (US EPA): ~$51–190 per tonne (contested).
Annual Sequestration Rates by Species Fast-growing trees (Poplar, Eucalyptus, Willow): 20–50 kg C/year Medium-growth (Oak, Maple, Birch): 10–25 kg C/year Slow-growth (Cedar, Spruce, Douglas fir): 5–15 kg C/year Tropical trees (Teak, Mahogany): 15–40 kg C/year Bamboo (technically grass): 5–35 kg C/year
Above-Ground vs Total Biomass Above-ground: trunk, branches, leaves, and the easiest part to measure Below-ground (roots): typically 20–30% of above-ground biomass Soil organic matter: significant long-term carbon pool Total carbon ≈ 1.2–1.5 × above-ground carbon
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.