EV vs Gas Lifetime CO₂ Calculator
Compare the lifetime driving CO₂ of an electric car against a gasoline car over the same miles.
How it works
Gas CO₂ = (miles ÷ mpg) × 8.887 · EV CO₂ = (miles ÷ mi-per-kWh) × grid factor · Saved = gas − EV
This compares tailpipe-and-grid CO₂ over a car’s driving life. The gas car burns miles ÷ mpg gallons, each releasing 8.887 kg of CO₂. The EV consumes miles ÷ efficiency kilowatt-hours, whose CO₂ depends entirely on how clean the grid is. On an average grid the EV usually wins by a wide margin; on a coal-heavy grid the gap narrows. Battery manufacturing adds a one-time carbon debt not counted here, typically repaid within the first couple of years of driving.
Worked example
Over 150,000 miles a 30 mpg car burns 5,000 gallons for about 44,435 kg of CO₂. A 3.5 mi/kWh EV uses ~42,857 kWh; on a 0.4 kg/kWh grid that is about 17,143 kg — so the EV saves roughly 27,300 kg, a 61% cut.
Sources: EPA — Electric Vehicle Myths
Frequently asked questions
Does this include making the battery?
No. Building an EV, especially its battery, creates a one-time carbon debt (often cited around 5–8 tonnes) that this operational comparison omits. On most grids the driving savings repay that debt within one to three years.
When does gas come out ahead?
Only on an exceptionally dirty grid combined with an efficient hybrid. Above roughly 0.6–0.7 kg CO₂ per kWh, a very efficient gas car can rival an EV on operating emissions.
Why does grid intensity matter so much?
An EV shifts emissions from the tailpipe to the power plant, so its footprint is only as clean as the electricity it charges on. As grids decarbonise, every existing EV gets cleaner automatically.
Related calculators
This calculator is for educational purposes. Double-check important results before acting on them.