Electric Vehicle Efficiency Converter
Convert EV energy consumption between Wh/km, Wh/mile, miles per kWh, km per kWh, and MPGe.
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Quick Reference
Tesla Model 3 Long Range: ~150 Wh/km = 4.4 miles/kWh = 141 MPGe
Efficient economy EV: ~120 Wh/km = 5.4 miles/kWh = 113 MPGe
Large EV truck: ~300 Wh/km = 2.1 miles/kWh = 56 MPGe
Efficient economy EV: ~120 Wh/km = 5.4 miles/kWh = 113 MPGe
Large EV truck: ~300 Wh/km = 2.1 miles/kWh = 56 MPGe
Electric vehicle efficiency measures how much energy a car uses per unit of distance. Unlike gasoline cars (which use L/100km or mpg), EVs use energy metrics.
The core unit is Wh/km (watt-hours per kilometer):
- A smaller number means a more efficient vehicle (uses less energy per km)
- A larger number means more energy per km (heavier, less aerodynamic, or more powerful car)
Key conversion relationships:
- Wh/km → Wh/mile: Wh/mile = Wh/km × 1.60934
- Wh/km → km/kWh: km/kWh = 1000 ÷ Wh/km (they are reciprocals)
- Wh/km → miles/kWh: miles/kWh = 1000 ÷ (Wh/km × 1.60934)
- Wh/km → MPGe: MPGe = 33,705 ÷ (Wh/mile) — the US EPA formula
MPGe (Miles per Gallon equivalent): The US EPA defined 33.7 kWh as the energy equivalent of one gallon of gasoline. MPGe = 33,705 Wh ÷ Wh/mile
Typical EV efficiency ranges:
- Small/efficient EV (e.g., Tesla Model 3): ~140–165 Wh/km (3.5–5 miles/kWh, 130–135 MPGe)
- Mid-size EV (e.g., Rivian R1T): ~250–300 Wh/km (2.2–2.7 miles/kWh, 73–80 MPGe)
- Large EV truck/SUV: ~300–400 Wh/km (1.7–2.2 miles/kWh, 55–70 MPGe)
- Cold weather impact: EVs typically use 15–40% more energy in temperatures below 0°C (32°F)
- Highway vs city: Unlike gas cars, EVs are often more efficient in city driving due to regenerative braking
Comparing EV and gasoline cost per km:
- Average gas car (8 L/100km at $1.60/L) = $0.128 per km
- Average EV (160 Wh/km at $0.15/kWh) = $0.024 per km
- EVs are typically 4–6x cheaper to fuel per km in most countries