EV CO2 Emissions Estimator
Calculate the carbon footprint of your electric car based on your electricity source.
What this calculator does
Estimate annual EV operating emissions using your driving distance, efficiency, and grid carbon intensity. You can also compare against a gasoline vehicle using MPG to estimate annual CO2 savings and a rough tree-equivalent figure.
Inputs explained
- Annual distance: Miles or kilometers driven per year.
- EV efficiency: mi/kWh or kWh/100km.
- Grid carbon intensity: Grams of CO2 per kWh (gCO2/kWh).
- Gas car MPG: Optional comparison for gasoline emissions.
How it works / Method
- Convert EV efficiency to kWh per mile or kilometer.
- Multiply by annual distance to get total kWh.
- Multiply kWh by grid intensity to estimate EV CO2.
- If MPG is provided, estimate gasoline CO2 using EPA emissions per gallon.
- Compute savings and a rough tree equivalent.
Formula(s) used
EV_kWh = distance * kWh_per_unit
EV_CO2_kg = EV_kWh * grid_g_per_kWh / 1000
Gas_gal = miles / MPG
Gas_CO2_kg = Gas_gal * 8.887
CO2_saved = Gas_CO2_kg - EV_CO2_kg
Trees_equiv = CO2_saved / 20
Assumes 8.887 kg CO2 per gallon of gasoline and ~20 kg CO2 per tree per year (rough).
Inputs
Carbon Footprint
Annual EV Emissions
-
Gas Car Emissions
-
CO2 Saved
-
Equivalent Trees Planted
-
*Gas emissions estimate 8.89 kg
CO2 per gallon.
Step-by-step example
Example inputs: 12,000 miles per year, 3.5 mi/kWh, grid intensity 400 gCO2/kWh, gas car 25 MPG.
- EV energy: 12,000 * (1 / 3.5) = 3,429 kWh.
- EV CO2: 3,429 * 400 / 1000 = 1,371 kg CO2.
- Gasoline: 12,000 / 25 = 480 gallons.
- Gas CO2: 480 * 8.887 = 4,266 kg CO2.
- CO2 saved: 4,266 - 1,371 = 2,895 kg CO2.
- Trees equivalent: 2,895 / 20 = about 145 trees.
Use cases
- Compare EV emissions across different grid intensities.
- Estimate annual CO2 savings versus a gasoline vehicle.
- Quantify emissions for reports or sustainability goals.
- Compare emissions changes after moving to a new region.
- Estimate impact of efficiency changes on emissions.
- Translate emissions into a simple tree-equivalent figure.
Assumptions & limitations
- Uses average grid intensity and does not model time of day variations.
- Charging losses are not included and may increase real emissions.
- Tree equivalence is a rough estimate and varies by species and location.
- Does not include vehicle manufacturing or battery production emissions.
- Gasoline emissions are based on a fixed EPA factor per gallon.
- Results are estimates for planning and comparison only.
Disclaimer: Results are estimates for planning only. Actual emissions depend on grid mix and driving conditions.
Frequently Asked Questions
Grid carbon intensity is the amount of CO2 emitted per kWh of electricity delivered, usually
reported in grams of CO2 per kWh. It varies by region depending on the mix of coal, gas, nuclear,
and renewables. A lower intensity means cleaner electricity and lower EV emissions. Use a value
for your region or a national average if you are unsure.
In the United States, the EPA eGRID database provides regional emissions factors. Many utilities
also publish emissions intensity or fuel mix on annual reports. If you cannot find a local
number, use a national or regional average for planning. The input can be adjusted later as you
get more precise data.
No. The calculator estimates emissions based on vehicle energy use. Charging losses between the
wall and the battery can increase actual grid energy. If you want a more conservative estimate,
increase the efficiency value or multiply kWh by an additional loss factor before using the
grid intensity.
Gasoline emissions are calculated using the EPA factor of about 8.887 kg CO2 per gallon of
gasoline burned. The calculator converts your annual miles and MPG into gallons used, then
multiplies by that factor. This provides tailpipe CO2 emissions and does not include upstream
oil production emissions.
The tree figure is a rough, easy-to-understand comparison. It divides CO2 savings by about 20 kg
CO2 per tree per year, which is a simplified assumption. Real tree sequestration varies widely
by species, climate, and age. Use the number as a communication aid rather than a precise
accounting tool.
No. This tool estimates operational emissions from driving only. It does not include vehicle or
battery manufacturing, end-of-life, or fuel production emissions. Those lifecycle factors can be
important for deeper analysis. For a simple operational comparison, this calculator provides a
clear and quick estimate.
Sources & references
- U.S. EPA: Greenhouse gas emissions from a gallon of gasoline - Source for 8.887 kg CO2 per gallon.
- U.S. EPA: eGRID - Grid emissions intensity data source.
- U.S. Energy Information Administration: Measuring electricity - Defines kWh units used in calculations.
- Schema.org: FAQPage, WebPage, and BreadcrumbList - Structured data definitions used on this page.