Electricity Carbon Intensity Calculator

Enter your monthly electricity usage (kWh), time span (months), and select your country or region to get the carbon intensity (gCO₂/kWh) of your grid. The Electricity Carbon Intensity Calculator returns your total CO₂ emissions (kg), monthly emissions, and equivalent real-world impacts like cars driven or trees needed to offset your usage. Also try the Remote Work Carbon Savings Calculator.

kWh

Your average monthly electricity consumption in kilowatt-hours.

Months

Number of months to calculate emissions over.

Carbon Intensity Source *

Select your country to use its 2022 grid carbon intensity (source: Our World in Data).

gCO₂/kWh

Enter a specific grid carbon intensity value in grams of CO₂ per kWh.

Results

Total CO₂ Emissions

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CO₂ per Month

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Carbon Intensity Applied

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Total Electricity Used

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Equivalent Cars Driven (1 Year)

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Trees Needed to Offset (10 yrs)

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Results Table

What is carbon intensity of electricity?

Carbon intensity refers to the amount of carbon dioxide (CO₂) emitted per unit of electricity generated, typically expressed in grams of CO₂ per kilowatt-hour (gCO₂/kWh). It varies widely by country and region depending on the mix of energy sources — grids powered mostly by renewables or nuclear have very low intensity, while coal-heavy grids have much higher values. See also our Carbon Footprint Calculator (Individual).

Why does carbon intensity differ by country?

Each country's electricity grid uses a different mix of energy sources — coal, natural gas, hydro, nuclear, solar, wind, and others. Countries like France (nuclear-heavy) and Switzerland (hydro-heavy) have very low carbon intensity, while coal-dependent grids like Poland and South Africa emit much more CO₂ per kWh. The fuel mix, grid efficiency, and share of renewables all affect the final intensity figure.

What does gCO₂/kWh mean?

gCO₂/kWh stands for grams of carbon dioxide equivalent per kilowatt-hour of electricity consumed. It is the standard unit for measuring grid carbon intensity. For example, if your grid has an intensity of 367 gCO₂/kWh (the US average), consuming 1,000 kWh produces approximately 367 kg of CO₂.

How do I find my monthly electricity usage in kWh?

Your monthly kWh consumption is printed on your electricity bill, usually under 'Energy Used' or 'Consumption'. You can also find it on your utility's online portal or smart meter app. The average US household uses around 900 kWh per month, though this varies significantly by home size, climate, and appliances. You might also find our calculate Total Embodied CO₂, Structure & Materials CO₂ & Site Ecosystem Carbon Release — Construction Carbon Footprint useful.

What is the average carbon intensity of electricity in the USA?

According to Our World in Data (2022), the US electricity grid has a carbon intensity of approximately 367 gCO₂/kWh. This varies by region — states with more renewables or nuclear power have lower figures, while states heavily reliant on coal or natural gas will be higher. The EPA's eGRID database provides sub-regional data for more precise estimates.

How is total CO₂ calculated from kWh usage?

The formula is: Total CO₂ (kg) = (Monthly kWh × Number of Months × Carbon Intensity in gCO₂/kWh) ÷ 1000. For example, 900 kWh/month over 12 months at 367 gCO₂/kWh gives 900 × 12 × 367 / 1000 = 3,963.6 kg of CO₂. Dividing by 1000 converts from grams to kilograms.

How many trees would it take to offset my electricity emissions?

A single urban tree seedling grown for 10 years sequesters approximately 60 kg of CO₂. This calculator divides your total CO₂ emissions by 60 to estimate the number of trees required to offset your usage over that period. This is an approximation — actual sequestration rates vary by species, climate, and soil conditions.

Can I use a custom carbon intensity value instead of a country average?

Yes. If you know your specific regional or utility grid carbon intensity — for example from your energy provider, a national registry like eGRID (USA), or a real-time carbon API — you can select 'Enter Custom Intensity' and input that value directly in gCO₂/kWh. This gives a more accurate result than country-level averages.