National Tree Carbon Sequestration Calculator
Estimate how much carbon dioxide (CO₂) your trees sequester annually and over their lifetime, based on species type, tree count, and average age. Uses USDA Forest Service sequestration rate data.
Formula
Annual CO₂ per tree (lbs) = Base Rate × Age Modifier × Setting Factor
Total Annual CO₂ (lbs) = Annual CO₂ per tree × Number of Trees
Lifetime CO₂ (lbs) = Σ [Base Rate × AgeModifier(age + y) × Setting × Count] for y = 0 … lifespan−1
(trapezoid numerical integration, 1-year steps)
Age Modifier (piecewise linear):
age ≤ 40 yr : 0.30 + 0.70 × (age / 40)
40 < age ≤ 100 yr : 1.00
100 < age ≤ 200 yr : 1.00 − 0.40 × ((age − 100) / 100)
age > 200 yr : max(0.40, 0.60 − 0.20 × ((age − 200) / 100))
Unit conversions: 1 lb = 0.4536 kg; 1 short ton = 2,000 lbs
Car equivalency: EPA average 404 g CO₂/mile → 2,481 miles per short ton CO₂
Assumptions & References
- Base sequestration rates derived from USDA Forest Service urban forestry fact sheets and McPherson et al. (2006), Urban Forests and Climate Change.
- Large hardwood (e.g., oak, maple) peak rate: 48 lbs CO₂/tree/yr; large conifer (e.g., pine, fir): 35 lbs CO₂/tree/yr.
- The age-growth modifier reflects that young trees sequester less carbon than mature trees; very old trees show gradual decline in net sequestration.
- Setting factors: Rural/Forest = 1.0 (optimal growth); Suburban = 0.8; Urban = 0.6 (soil compaction, heat stress, limited root space).
- Rates represent gross CO₂ sequestration; decomposition after tree death is not included.
- Car equivalency based on U.S. EPA estimate of 404 g CO₂ per mile for an average passenger vehicle (2023).
- Results are estimates. Actual sequestration varies by climate, soil quality, precipitation, and individual tree health.
- For large-scale or policy-level analysis, consult the i-Tree Tools suite (USDA Forest Service / Davey Institute).