Fuel and Emissions
Tailpipe CO2 per Mile Calculator
Estimate direct tailpipe carbon dioxide per mile from fuel economy and a fuel emission factor. This does not include fuel production, vehicle manufacturing, or non-CO2 pollutants.
Replace the example values
Check labels, prefixes, suffixes, and percentage bases before calculating.
The measurement being modeled
Estimate direct tailpipe carbon dioxide per mile from fuel economy and a fuel emission factor — treat the output as a measured relationship for one operating case.
This does not include fuel production, vehicle manufacturing, or non-CO2 pollutants — that condition defines when tailpipe co2 per mile is comparable with another result.
After recording this output, use the Tire-Size-Corrected MPG to correct MPG when a tire-diameter change alters the odometer distance.
Input reference points
For CO2 per gallon burned, use the quantity described as tailpipe carbon dioxide attributed to one gallon of fuel — in the vehicle record, match the fuel quantity to the same distance, fill method, and operating period.
Vehicle fuel economy is defined here as miles traveled per gallon — keeping that definition intact requires you to match the fuel quantity to the same distance, fill method, and operating period.
Vehicle occupants. Average people carried for per-person context — for this measurement, use a measurement or specification from the exact component and operating condition being evaluated.
Turning the inputs into a result
In “CO2 per mile = kilograms CO2 per gallon ÷ MPG,” the calculation does not infer a missing vehicle measurement.
No term beyond co2 per gallon burned, vehicle fuel economy, and vehicle occupants is introduced in “CO2 per mile = kilograms CO2 per gallon ÷ MPG.”
Tailpipe CO2 per mile answers “Estimate direct tailpipe carbon dioxide per mile from fuel economy and a fuel emission factor.” The additional displays, CO2 per 100 miles and CO2 per person-mile, are a different view of the same entered measurements.
Use the emission factor for the actual fuel — when that condition changes, compare separate calculator runs instead of blending the inputs.
Because this does not include fuel production, vehicle manufacturing, or non-CO2 pollutants, a disagreement between tailpipe co2 per mile and an outside reference should trigger a review of co2 per gallon burned and vehicle occupants.
Operating conditions outside the formula
The equation cannot determine whether vehicle occupants was recorded with a calibrated instrument or under a repeatable operating condition — for vehicle occupants, the page specifically expects average people carried for per-person context.
A record that can be revisited
The calculation file for Tailpipe CO2 per Mile should include the source behind co2 per gallon burned (tailpipe carbon dioxide attributed to one gallon of fuel) and the source behind vehicle occupants (average people carried for per-person context).
The operating record is incomplete without the limitation “This does not include fuel production, vehicle manufacturing, or non-CO2 pollutants,” which determines whether the next result is comparable.
Before using this result
What measurement source fits CO2 per gallon burned when it represents tailpipe carbon dioxide attributed to one gallon of fuel?
Because co2 per gallon burned represents tailpipe carbon dioxide attributed to one gallon of fuel, use a source tied to the exact vehicle, component, and operating period described by the other fields.
How does the warning “This does not include fuel production, vehicle manufacturing, or non-CO2 pollutants” affect Tailpipe CO2 per mile?
The condition “This does not include fuel production, vehicle manufacturing, or non-CO2 pollutants” is not corrected automatically by the numeric inputs, so create a separate tailpipe co2 per mile case when it changes.