How MPG vs MPGe Cost Comparator Works?
This tool works by subtracting an electric vehicle's cost per 100 miles from a gasoline car's cost per 100 miles. MPG means miles per gallon and MPGe means miles per gallon equivalent.
Price the gas car per 100 miles
Divide 100 by MPG and multiply by the gas price. 30 MPG at $3.60 per gallon costs $12.00.
Price the EV per 100 miles
Use the EV's MPGe and electricity rate. 110 MPGe at $0.16 per kilowatt-hour (kWh) costs about $4.89.
Enter both costs
Type each cost per 100 miles into the matching field.
Read the difference
The tool returns the dollar gap for every 100 miles (161 km).
MPG vs MPGe Cost Comparator Formula
The formula is Difference = Gas Cost per 100 Miles − EV Cost per 100 Miles.
Difference = |Gas $/100 mi − EV $/100 mi|Formula variables
- Gas $/100 mi
- (100 ÷ MPG) × Price per Gallon.
- EV $/100 mi
- (100 ÷ MPGe) × 33.7 kWh × Price per kWh.
- 33.7 kWh
- Energy in 1 gallon of gasoline, the EPA basis for MPGe.
Worked example
- Gas Car (30 MPG @ $3.60/gal): $12.00/100mi
- EV (110 MPGe @ $0.16/kWh): $4.89/100mi
- Gas car: (100 ÷ 30) × $3.60 = $12.00.
- EV: (100 ÷ 110) × 33.7 kWh = 30.6 kWh per 100 miles, about $4.89 at $0.16 per kWh.
- Difference: $12.00 − $4.89 = $7.11 per 100 miles.
Result: $7.11 ($/100 mi difference)
MPGe measures energy efficiency, not cost. 2 EVs with the same MPGe cost different amounts per mile in states with different electricity rates.
MPG vs MPGe Cost Comparator Conversion Table
The table shows the cost gap per 100 miles for 3 gas costs against 3 EV costs.
Rows: Gas Car (30 MPG @ $3.60/gal) ($/100mi). Columns: EV (110 MPGe @ $0.16/kWh) ($/100mi). Cells: $/100 mi difference.
| $/100mi | $3.00/100mi | $4.89/100mi | $7.00/100mi |
|---|---|---|---|
| $8.00/100mi | $5.00 | $3.11 | $1.00 |
| $12.00/100mi | $9.00 | $7.11 | $5.00 |
| $16.00/100mi | $13.00 | $11.11 | $9.00 |
A gas car costing $16 per 100 miles and an EV costing $3 per 100 miles differ by $13.00 every 100 miles.
What is MPG vs MPGe Cost Comparator?
The MPG vs MPGe Cost Comparator is a tool that compares gas and electric driving costs on a common 100-mile basis. The tool translates MPG and MPGe labels into dollars.
The US Environmental Protection Agency (EPA) created MPGe so EV efficiency fits the familiar MPG scale. 1 gallon of gasoline holds the same energy as 33.7 kWh of electricity.
MPGe alone does not show cost. Cost per 100 miles depends on local gas and electricity prices, and the comparator brings both together.
What are the uses of MPG vs MPGe Cost Comparator?
There are 4 main uses of the MPG vs MPGe Cost Comparator: reading EPA window stickers, comparing EVs with gas cars, testing local electricity rates, and explaining EV costs to buyers.
Reading EPA window stickers
Shoppers turn MPG and MPGe labels into dollar figures.
Comparing EVs with gas cars
Buyers see the cost gap per 100 miles.
Testing local electricity rates
Drivers check how high rates shrink the EV advantage.
Explaining EV costs to buyers
Dealers show customers a clear dollar comparison.
Need every metric in one place? Open the main MPG Cost Calculator or browse all 101 fuel calculators.