Miles per kWh Calculator
Compute electric vehicle efficiency in miles per kWh, kWh per 100 miles and approximate MPGe from distance and energy used.
Results
Miles per kWh
- kWh per 100 miles
- 28.0
- Approx. MPGe
- 120.4
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Educational estimates · not financial advice · free, no signup
Formula / how it works
mi/kWh = miles ÷ kWh. kWh/100 mi = 100 ÷ (mi/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
Electric vehicle efficiency is the energy used to cover a distance. It is quoted as miles per kilowatt-hour in the US, as kWh per 100 miles or 100 km elsewhere. This calculator takes the distance you drove and the energy used and gives all the common forms plus approximate MPGe. EV drivers use it to track real-world efficiency from the trip computer or a charging record, compare with the official rating, and estimate running costs. It does not account for charging losses unless you measure energy at the wall.
When to use / who it helps
- You want to compute your own EV efficiency from a trip.
- You are comparing summer and winter results.
- You want to estimate cost per mile from your tariff.
- You are comparing cars.
- You are converting between efficiency forms.
How to use
Steps
- Enter the distance driven in miles.
- Enter the energy used in kWh.
- Read miles per kWh.
- Read kWh per 100 miles.
- Read approximate MPGe.
- Multiply kWh per mile by your electricity price for cost.
How to interpret results
- Higher miles per kWh means better efficiency.
- Measurements at the wall include charging losses, which makes efficiency look lower.
- Winter, speed and heating reduce efficiency.
- Trip computers can differ from measured values.
- Use a long enough trip for a stable average.
Common mistakes & gotchas
- Using battery capacity instead of energy consumed.
- Mixing wall and battery energy.
- Comparing with a rating from a different test cycle.
- Using very short trips.
- Confusing miles per kWh with kWh per mile.
Worked example
Worked example — 250 miles using 70 kWh
- Miles per kWh: 250 ÷ 70 ≈ 3.57.
- kWh per 100 miles: 100 ÷ 3.571 = 28.0.
- MPGe: 3.571 × 33.7 ≈ 120.4.
- Cost at $0.15 per kWh: 28.0 × 0.15 = $4.20 per 100 miles.
Result: About 3.57 miles per kWh, 28 kWh per 100 miles, and 120 MPGe.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
mi/kWh = miles ÷ kWh. kWh/100 mi = 100 ÷ (mi/kWh). MPGe ≈ (mi/kWh) × 33.7.
Frequently asked questions
How many miles per kWh is good?
Many modern EVs achieve roughly 3 to 4 miles per kWh in mild conditions, but it varies.
How do I get kWh per 100 miles?
Divide 100 by miles per kWh.
Why is my efficiency worse in winter?
Cabin heating and battery temperature increase consumption.
Does it include charging losses?
Only if the energy figure was measured at the wall.
What is MPGe?
The EPA's gasoline-equivalent measure using 33.7 kWh per gallon.
How do I calculate cost per mile?
Multiply kWh per mile by your price per kWh.