What grid intensity should I use?

Use a recent factor that matches the electricity location, time period, reporting boundary, and purpose. For U.S. location-based estimates, EPA recommends eGRID subregion total output emission rates for electricity carbon footprinting.

What is the difference between average and marginal grid intensity?

Average intensity divides emissions across all generation in a period. Marginal or nonbaseload rates estimate generators likely to change output as demand changes. Use the factor that matches the question and required method.

Does this calculator include transmission losses?

Only when the factor you enter includes them. The tool does not add or remove line losses automatically, so document whether the selected factor is generation-based or delivered-electricity based.

Is CO2 the same as CO2e?

No. CO2 is carbon dioxide alone. CO2e combines greenhouse gases on a common warming basis. Select the label that matches your source; the calculator does not convert a CO2-only factor into CO2e.

Are my electricity inputs uploaded?

No. Calculations, copying, and CSV creation run in your browser. The page does not send the values you enter to a server.

Electricity Grid Carbon Intensity Calculator

Calculate CO₂ or CO₂e from electricity use or average load, or derive a grid output emission rate from total emissions and generation. Everything runs locally in your browser.

Electricity and emissions data

What do you want to calculate?

Emissions from energy Emissions from load + time Derive grid intensity

Electricity used

Electricity amountUse billed, metered, modeled, or generated electricity. Energy unit

Grid emission factor

Grid carbon intensity400 is an editable example, not a live or local grid value. Intensity unit Greenhouse-gas basisChoose the label used by the factor source.

Factor boundary: enter a recent average or marginal factor that matches your location, period, and purpose. Line losses are included only if your source includes them.

Result

1,000 kWh at 400 g CO₂e/kWh produces 400 kg CO₂e.

Total electricity emissions400 kg CO₂e0.4 metric tonnes CO₂e

Electricity1,000 kWh1 MWh

Grid intensity400 g CO₂e/kWh400 kg CO₂e/MWh

Calculation steps

Normalize energy: 1,000 kWh
Normalize factor: 400 g/kWh = 0.4 kg/kWh
Multiply: 1,000 kWh × 0.4 kg/kWh = 400 kg CO₂e

The result inherits the boundary, gas basis, time period, and loss treatment of the factor entered.

Last reviewedAugust 3, 2026

Emissions equationElectricity × grid emission factor

Intensity equationTotal emissions ÷ generation

PrivacyNo input upload or input tracking

How to Use the Grid Carbon Intensity Calculator

Choose the direction. Start with metered energy, average load and time, or grid-wide emissions and generation.
Match every unit. Select the units printed on bills, meters, inventories, or grid data. The calculator normalizes them before multiplying or dividing.
Match the emissions label. Choose CO₂ when the source covers carbon dioxide only, or CO₂e when it combines greenhouse gases.
Check the boundary. Average versus marginal, generation versus delivered electricity, gross versus net generation, and line-loss treatment can all change the meaning.
Review and export. Confirm the substituted equation, then copy the summary or save the CSV.

Formulas and Unit Conversions

Electricity emissions (kg) = electricity used (kWh) × grid intensity (kg/kWh)Electricity from average load (kWh) = average load (kW) × operating time (hours)Grid carbon intensity (g/kWh) = total grid emissions (g) ÷ electricity generation (kWh)

Useful identity: 1 g/kWh = 1 kg/MWh = 1 metric tonne/GWh. To convert lb/MWh to g/kWh, multiply by 0.45359237. To convert g/kWh to lb/MWh, divide by 0.45359237.

Interpretation limit: This tool performs arithmetic and unit conversion; it does not fetch live grid conditions or decide which accounting factor is appropriate. Formal inventories may prescribe supplier data, residual mixes, contractual instruments, location-based factors, or market-based factors.

Worked Examples

Electricity-use estimate

1,000 kWh × 400 g CO₂e/kWh = 400,000 g CO₂e = 400 kg CO₂e.

Average electrical load

5 kW × 8 h = 40 kWh. At 400 g CO₂e/kWh, emissions are 16,000 g = 16 kg CO₂e.

Derive a grid output rate

400 metric tonnes CO₂e ÷ 1,000 MWh = 400 kg/MWh = 400 g/kWh = 881.85 lb/MWh.

Choosing and Documenting a Grid Factor

An output emission rate is emissions divided by electricity generation. EPA eGRID publishes U.S. plant and regional generation, emissions, and output rates. EPA recommends eGRID subregion total output emission rates for carbon-footprinting electricity purchases because the subregion more closely represents the grid serving a location.

Average rate: use when allocating the emissions of the electricity mix across consumption in a period. Marginal or nonbaseload rate: use only when estimating a change in generation or avoided electricity under a method that calls for it. They answer different questions and should not be mixed without explanation.

For a reproducible result, record the data year, geography, CO₂ or CO₂e basis, average or marginal method, gross or net generation, and whether line losses are included. Do not compare a delivered-electricity factor directly with a plant-output factor without reconciling that boundary.

Primary methodology sources

U.S. EPA — Frequent Questions About eGRID: output-rate equation, recommended regional rate for electricity footprints, and average versus nonbaseload use.
U.S. EPA — Using eGRID to Determine the Emissions from Electricity Use: applying total output emission rates to electricity consumption.
U.S. EPA — eGRID Summary Data: published CO₂ and CO₂e output rates by eGRID subregion.
GHG Protocol Scope 2 Guidance: location-based and market-based electricity-accounting approaches and data hierarchies.

Frequently Asked Questions

How do you calculate emissions from electricity use?

Convert electricity to kWh and the factor to kg/kWh, then multiply. For example, 1,000 kWh × 400 g/kWh ÷ 1,000 g/kg = 400 kg.

How do you calculate grid carbon intensity?

Divide emissions by generation for the same grid, time, and boundary. The result can be shown as g/kWh, kg/MWh, or lb/MWh.

Is g/kWh the same numeric value as kg/MWh?

Yes. A value of 400 g/kWh is exactly 400 kg/MWh. It converts to about 881.85 lb/MWh.

What factor should I use?

Use a recent source that matches the location, reporting period, emissions scope, and purpose. For U.S. electricity footprints, EPA recommends an eGRID subregion total output emission rate.

What is average versus marginal intensity?

Average intensity allocates emissions across all generation. Marginal or nonbaseload rates estimate generators likely to respond when demand changes. Neither is universally interchangeable with the other.

Are transmission and distribution losses included?

Only if the factor entered includes them. The calculator does not apply a hidden loss adjustment.

Is CO₂ the same as CO₂e?

No. CO₂ covers carbon dioxide; CO₂e expresses several greenhouse gases on a common warming basis. Select the basis published by your source.

Can I use this for formal Scope 2 reporting?

Use it as an arithmetic and unit-conversion aid. Follow the required standard for location-based and market-based data, certificates, residual mixes, losses, and documentation.

Are my inputs uploaded?

No. Calculation, copying, and CSV export happen locally in your browser.