Electricity Carbon Calculator
Calculate CO₂ emissions from electricity usage. Enter monthly kWh and select your grid region to get monthly CO₂ in lbs, annual CO₂ in tons, and trees needed to offset.
kWh
Monthly CO₂ (lbs)
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Annual CO₂ (short tons) —
Trees Needed to Offset (annual) —
Emission Factor Used —
Extended More scenarios, charts & detailed breakdown ▾
kWh
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Monthly CO₂ (lbs)
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Annual CO₂ (tons) —
Net CO₂ after Renewables (tons) —
Trees to Offset Net —
Professional Full parameters & maximum detail ▾
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kWh
Emissions
Monthly CO₂ (lbs) —
Annual CO₂ (tons) —
Net CO₂ after Renewables (tons) —
Offset & Cost
Trees to Offset Net (annual) —
REC Equivalent (MWh/yr if 100% offset) —
Carbon Cost (social cost basis) —
Tracking & Reporting
Year-over-Year CO₂ Change —
Scope 2 Reporting Note —
How to Use This Calculator
- Enter your monthly kWh usage from your electricity bill.
- Select your grid region (US regional or EU/UK).
- Click Calculate to see monthly CO₂ in lbs and annual CO₂ in tons.
- Use Business Usage for Scope 2 reporting needs.
- Use Compare Regions to see how the same kWh produces different emissions in two grids.
Formula
CO₂ (lbs) = kWh × emission factor (lbs/kWh) • Annual CO₂ (tons) = monthly CO₂ × 12 / 2000 • Trees needed = annual CO₂ (lbs) / 48
Example
500 kWh/month × US average 0.855 lbs/kWh = 427.5 lbs/month → 2.57 tons/year → 107 trees to offset annually.
Frequently Asked Questions
- It depends on your grid region. The US average is about 0.855 lbs CO₂ per kWh. Coal-heavy grids (Midwest) can exceed 1.6 lbs/kWh while clean grids (Northwest) can be under 0.2 lbs/kWh due to hydropower.
- eGRID (Emissions & Generation Resource Integrated Database) from the EPA provides regional electricity emission factors. They account for the mix of generation sources (coal, gas, nuclear, renewables) in each grid region.
- One mature tree absorbs about 48 lbs (22 kg) of CO₂ per year. To offset 1 metric ton (2,205 lbs) of CO₂ annually, you need roughly 45–50 trees.
- A REC represents 1 MWh (1,000 kWh) of electricity generated from a renewable source. Buying RECs lets you claim your electricity is renewably sourced, enabling market-based Scope 2 reporting.
- Scope 2 covers indirect emissions from purchased electricity. Location-based Scope 2 uses the average grid emission factor. Market-based Scope 2 reflects actual power purchase agreements and RECs, allowing for zero-emission claims if renewable energy is purchased.