MPGe Calculator (Electric Vehicle Efficiency)
Convert an EV's energy use (kWh per 100 miles) to MPGe — miles per gallon gasoline-equivalent — using the EPA 33.7 kWh/gallon standard. Runs in your browser.
From the EV’s window sticker / EPA rating. Efficient EVs use ~25–30; larger ones 35–45.
MPGe (miles per gallon gasoline-equivalent) lets you compare an EV’s efficiency to a gas car. The EPA defines 33.7 kWh of electricity as the energy in one gallon of gasoline, so MPGe = 33.7 × 100 ÷ (kWh per 100 miles). It measures energy efficiency, not running cost — actual cost depends on your electricity price (¢/kWh), which is usually far cheaper per mile than gasoline. Everything runs in your browser.
About this tool
MPGe — miles per gallon of gasoline-equivalent — is the rating the US Environmental Protection Agency created so that the efficiency of electric and other alternative-fuel vehicles can be compared on the same scale as a traditional gas car's MPG. The whole system rests on one defined equivalence: the EPA states that 33.7 kilowatt-hours of electricity contains the same amount of energy as one US gallon of gasoline. From that, the conversion is direct — MPGe equals 33.7 multiplied by 100, divided by the vehicle's energy use in kilowatt-hours per 100 miles (the figure shown on an EV's window sticker). So an EV that consumes 30 kWh per 100 miles rates about 112 MPGe, and a very efficient one using 25 kWh per 100 miles rates about 135 MPGe. This calculator does that conversion and also shows the equivalent in miles per kWh, the unit many EV drivers prefer for everyday tracking. The crucial thing to understand about MPGe is what it does and does not tell you: it measures energy efficiency — how far the vehicle travels per unit of energy — not how much it costs to drive. Because electricity is usually far cheaper per unit of energy than gasoline, an EV's cost per mile is typically much lower than its MPGe alone would suggest when compared to a gas car's fuel bill; to get actual running cost you multiply energy use by your local electricity rate in cents per kWh. MPGe also doesn't capture charging losses or how efficiency drops in cold weather or at highway speeds. Still, as a standardized efficiency yardstick it's the best single number for comparing EVs to each other and to gas vehicles. Everything runs in your browser; nothing is uploaded.
How to use it
- Find your EV's energy use in kWh per 100 miles (on the window sticker or EPA listing).
- Enter that number.
- Read the MPGe and the equivalent miles per kWh.
- For running cost, multiply kWh used by your electricity rate separately — MPGe is efficiency, not cost.
Frequently asked questions
- How is MPGe calculated?
- MPGe = 33.7 × 100 ÷ (kWh per 100 miles), because the EPA defines 33.7 kWh as energy-equivalent to one gallon of gasoline. An EV using 30 kWh/100 mi is about 112 MPGe.
- Why 33.7 kWh per gallon?
- That is the EPA's official figure for the energy content of one US gallon of gasoline expressed in electricity. It is the basis of every MPGe rating, allowing electric and gas vehicles to be compared on one scale.
- Does a high MPGe mean low fuel cost?
- Not directly. MPGe measures energy efficiency, not cost. Because electricity is usually cheaper per unit of energy than gasoline, an EV's cost per mile is typically much lower than the MPGe-vs-MPG comparison implies. Use your ¢/kWh rate for cost.
- What is a good MPGe?
- Efficient EVs rate roughly 110–140 MPGe; larger trucks and SUVs run lower (around 60–90 MPGe). Higher is more energy-efficient, meaning fewer kWh per mile.
- What is MPGe in miles per kWh?
- Divide 100 by the kWh-per-100-miles to get miles per kWh — e.g. 30 kWh/100 mi is about 3.3 mi/kWh. Many EV drivers track this unit directly; the tool shows both.
- Is anything uploaded?
- No. The conversion runs entirely in your browser.