MPGe Calculator
Convert EV efficiency from miles per kWh or kWh per 100 miles into MPGe using the 33.7 kWh per gallon convention, with a worked example and limits.
Results
MPGe
- mi/kWh
- 3.50
- kWh/100 mi
- 28.57
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Educational estimates · not financial advice · free, no signup
Formula / how it works
EPA convention: 1 gallon gasoline ≈ 33.7 kWh. MPGe = (mi/kWh) × 33.7.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
MPGe, miles per gallon equivalent, lets you compare electric vehicles with petrol cars on a single scale. The EPA defines one gallon of gasoline as having the energy of 33.7 kilowatt-hours of electricity. An EV that travels 3.5 miles on each kWh therefore covers 3.5 × 33.7 ≈ 118 miles on the energy equivalent of a gallon. MPGe measures energy efficiency, not cost or emissions. Electricity and fuel prices differ, so a higher MPGe does not guarantee lower running cost, and charging losses between the wall and the battery are not always included in a simple conversion.
When to use / who it helps
- You are comparing EV efficiency with a petrol car's mpg.
- You have a vehicle rating in kWh per 100 miles and want MPGe.
- You are reading a spec sheet that shows miles per kWh.
- You are discussing efficiency with a dealer or in a review.
- You want to go the other way from MPGe to consumption.
How to use
Steps
- Choose whether your input is miles per kWh or kWh per 100 miles.
- Enter the value.
- Read MPGe.
- Read the other efficiency forms for cross-checking.
- Compare with a petrol car's mpg for the same distances.
- Combine with energy prices to estimate cost per mile.
How to interpret results
- Higher MPGe and miles per kWh mean a more efficient vehicle; lower kWh per 100 miles is better.
- MPGe reflects energy, not price; cost needs your local electricity price.
- Official ratings and real consumption differ with speed, temperature and driving style.
- Well-to-wheel emissions depend on how the electricity is generated.
- Charging losses can raise the energy drawn from the wall by roughly 10–20% compared with battery energy.
Common mistakes & gotchas
- Reading MPGe as a cost comparison.
- Mixing miles per kWh with kWh per mile, which are inverses.
- Comparing MPGe with L/100 km without converting units.
- Ignoring charging losses.
- Using winter consumption for a yearly average.
Worked example
Worked example — 3.5 miles per kWh
- MPGe = 3.5 × 33.7 = 117.95, shown as about 118.
- kWh per 100 miles: 100 ÷ 3.5 ≈ 28.57.
- Compare with a 30 mpg petrol car: the EV uses roughly a quarter of the energy per mile.
- At $0.15 per kWh, 28.57 kWh costs about $4.29 per 100 miles.
Result: About 118 MPGe and 28.6 kWh per 100 miles.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
EPA convention: 1 gallon gasoline ≈ 33.7 kWh. MPGe = (mi/kWh) × 33.7.
Frequently asked questions
What does MPGe mean?
Miles per gallon equivalent: the distance an EV travels on the amount of electricity energy equal to a gallon of gasoline.
Where does 33.7 come from?
The US EPA's energy equivalence for a gallon of gasoline.
Is higher MPGe always cheaper to run?
Not necessarily, because electricity and fuel prices differ.
How do I convert kWh per 100 miles to miles per kWh?
Divide 100 by the kWh value.
Does MPGe include charging losses?
It depends on the rating; wall-to-wheels figures include them, battery-based ones do not.
How does this compare to L/100 km?
Convert using the unit-conversion guide, since the scales are inverse.