What biomass factors does this tool use?

The tool applies IPCC 2006 Guidelines for National Greenhouse Gas Inventories (Volume 4, Chapter 4) Tier 1 default biomass density values and biomass expansion factors (BEF) for each forest type. Above-ground biomass density ranges from ~60 t DM/ha for young boreal stands to ~300 t DM/ha for mature tropical moist forest.

How is below-ground biomass estimated?

Below-ground (root) biomass is estimated as a fraction of above-ground biomass using the IPCC root-to-shoot ratio (R). Values range from 0.20 for tropical forests to 0.40 for boreal forests, reflecting the relatively larger root systems in colder climates.

What carbon fraction and CO2 conversion are used?

A carbon fraction of 0.47 (47% of dry biomass mass is carbon) is applied following IPCC default values. The CO2-equivalent is then calculated by multiplying carbon mass by 44/12 (the molecular weight ratio of CO2 to C), giving t CO2e per t C.

How accurate are the estimates?

IPCC Tier 1 estimates carry uncertainty of ±30–50%. They are suitable for scoping and voluntary reporting but not for compliance-grade carbon credit verification, which requires Tier 2 or Tier 3 site-specific allometric equations and field measurements.

Does the tool include soil carbon?

No. Soil organic carbon (SOC) is not included because it varies enormously by soil type and climate and requires site-specific measurements. This tool covers the four main biomass pools: above-ground living biomass, below-ground biomass, dead wood, and litter.

What is meant by annual sequestration rate?

Annual sequestration is the incremental carbon uptake per year at the current stand age, derived from the derivative of the growth curve. Young stands grow quickly and sequester more per year; old-growth forests approach carbon neutrality as growth balances respiration and mortality.

Forest Carbon Calculator

Name: Forest Carbon Calculator
Availability: InStock
Author: Nham Vu

Enter your forest area, forest type, and stand age to estimate total carbon stored and annual sequestration in tonnes CO2-equivalent using IPCC biomass factors.

Forest Parameters

Forest Area (hectares)

1 hectare = 2.47 acres. Enter the total forested area to assess.

Forest Type

Select the forest type that best describes your stand.

Average Stand Age (years)

Age of the dominant tree cohort. Young stands (1–20 yrs) sequester carbon rapidly; mature stands hold the largest stock.

Fill in the forest parameters and click Calculate Carbon to see the estimate.

Calculated!

Summary

Enter your forest area, forest type, and stand age to estimate total carbon stored and annual sequestration in tonnes CO2-equivalent using IPCC biomass factors.

How it works

Enter your forest area in hectares (1 ha = 2.47 acres).
Select the forest type that best matches your stand (tropical, temperate, boreal, or plantation).
Enter the average stand age in years — older stands hold more biomass but grow more slowly.
Click Calculate to apply IPCC Tier 1 biomass density and expansion factors.
Review the total carbon stock, annual sequestration rate, and pool breakdown.

Use cases

Estimate carbon credits available from a reforestation or afforestation project.
Compare carbon storage across different forest types for conservation prioritization.
Screen forest parcels for voluntary carbon market eligibility.
Calculate the CO2e offset value of a woodland before land-use change decisions.
Support corporate nature-based solutions (NbS) reporting and net-zero claims.
Assess the annual sequestration benefit of a tree-planting program.
Educate landowners on the climate value of maintaining mature forest cover.
Provide a first-pass estimate for REDD+ project feasibility studies.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu