What inputs do I need?

Enter a CO₂ amount (kg or tonnes) and choose whether you want to offset it every year or over multiple years. Optionally adjust tree growth, survival, buffer, electricity grid intensity, and renewable yield.

Are these exact offsets?

No—this is a simple estimator. Actual offsets depend on project-specific factors (species, climate, management, additionality, permanence). All factors here are editable for transparency.

No. Everything runs locally in your browser. No data is sent to a server.

Carbon Offset Estimator — Trees or Renewable kWh

Friendly estimates for planning and awareness. Private by design — runs locally in your browser.

Offset Inputs

CO₂ amount Units Offset type Years (if total)

Offset Pathways

🌳 Trees / Reforestation

Avg sequestration (kg CO₂ / tree / year) Establishment (years at ~0) Ramp to full (years) Survival after planting

Permanence buffer (deduct %) Project duration (years)

Simple growth model: 0 during establishment, then linear ramp to full rate. You can edit all assumptions.

⚡ Renewable Energy (RECs / GOs)

Grid intensity displaced (kg CO₂ / kWh) Quality discount (%, optional)

Optional: estimate capacity size

Technology Yield (kWh / kW / year) System losses (%)

kWh needed = CO₂ ÷ grid intensity (adjusted for any discount). Capacity is kWh/year ÷ yield.

Advanced options (optional)

Show fractional trees kWh rounding

These toggles just change display rounding, not the underlying math.

Friendly estimate only. Real-world outcomes vary with species, climate, management, additionality, permanence, grid conditions, and certificate quality.

Results

How This Offset Estimator Works

This tool converts a CO₂ amount into either an equivalent number of trees (with a simple growth model) or renewable electricity (kWh) that would displace grid emissions. It’s designed to be non-judgmental and transparent—every assumption is editable.

Tree modeling (simple ramp)

Years 0 → establishment: ~0 kg/tree.
Then a linear ramp to full annual sequestration over “Ramp to full” years.
Applies survival and a permanence buffer (deducted %).

Renewable electricity

kWh needed = CO₂ ÷ grid intensity (kg/kWh), optionally discounted for quality.
Capacity estimate uses an annual yield (kWh/kW/yr) minus system losses.

Limitations

Offsets vary widely by project type, location, additionality, leakage, and permanence.
This is an estimator for awareness, not a certification or purchase tool.

FAQs

Annual vs. total offset?

Annual means matching the same amount every year (e.g., recurring emissions). Total spreads a one-time amount across N years of tree growth or annual renewable generation.

Why the ramp for trees?

Trees don’t sequester much in the first few years; this model ramps up to a steady annual rate for realism while staying simple.

Can I match a specific standard?

Yes. Adjust survival, buffer, sequestration rates, grid intensity, and yield to mirror a given methodology or registry.