akar.earthSingle Tree CO2 Calculator
Free single tree CO2 calculator: estimate above-ground biomass and CO2 stored in one tropical tree from diameter, height and wood density (Chave et al. 2014).
The single tree CO2 calculator estimates the above-ground biomass of one tropical tree and the total CO2 stored in it, from its diameter at breast height, height, wood density and root-to-shoot ratio. It uses the widely cited Chave et al. (2014) pantropical allometric equation.
Method
- Above-ground biomass (kg) = 0.0673 × (ρ × D² × H)^0.976, where ρ is wood density (g/cm³), D is DBH (cm) and H is total height (m).
- Total biomass = AGB × (1 + root-to-shoot ratio). The default 0.24 is a common tropical value; mangroves are often higher.
- Carbon = total biomass × 0.47, the IPCC default carbon fraction.
- CO2 = carbon × 44/12.
Assumptions
- The tree is a single-stemmed tropical tree within the size range the equation was built on.
- DBH is measured at 1.3 m, or above buttresses where present.
- Height is total height, measured rather than guessed.
- Wood density is a species or site value, not a global average.
Limitations
The pantropical model fits many species on average, but individual trees and some species groups, such as palms, bamboo, tree ferns and mangroves, can differ substantially. Coconut and oil palm need palm-specific equations. Very small trees and very large ones carry more error. Height errors carry through to biomass almost proportionally. Carbon projects use species-specific equations where published, and apply them to plots, not single trees.
How to read the result
The AGB figure is dry biomass above ground. The CO2 figure includes roots and is the amount of CO2 the tree has taken from the atmosphere and holds as long as it lives. It is not a carbon credit; credits require a project, a baseline, monitoring and verification. To understand the conversion steps, see CO2 from biomass. To scale up to a planting, use the ARR carbon estimator. For typical wood densities, see species pages such as teak or sengon, and the ARR hub. If you need plot-level estimates for a project, our field data campaigns measure and calculate them properly.
Frequently asked questions
How much CO2 does one tree store?
It depends on size and wood density. A small young tree may hold a few kilograms of CO2, while a large tropical tree can hold several tonnes. Enter the tree's diameter, height and wood density above to estimate it.
Which equation does this calculator use?
The Chave et al. (2014) pantropical equation with height: AGB = 0.0673 × (ρD²H)^0.976, where ρ is wood density in g/cm³, D is diameter at breast height in cm and H is height in m. The result is in kilograms.
Where do I find wood density for my species?
Use published wood density databases or species-specific studies. Values vary within a species, so use a range where possible. Our species pages give typical ranges for common Indonesian trees.