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EV Efficiency Converter — kWh/100 km ↔ mi/kWh ↔ Wh/mi ↔ MPGe

Convert electric car efficiency between kWh/100 km, kWh/100 mi, Wh/km, Wh/mi, km/kWh, mi/kWh and MPGe (33.7 kWh per gallon), plus the gasoline-equivalent L/100 km.

Efficiency value

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How it works

Wh/km = kWh/100 km × 10 · Wh/mi = Wh/km × 1.609344 · mi/kWh = 1,000 ÷ Wh/mi · km/kWh = 1,000 ÷ Wh/km · MPGe = 33,705 ÷ Wh/mi (33.705 kWh = energy in one US gallon of gasoline) · gasoline-equivalent L/100 km = kWh/100 km ÷ 8.904 (kWh per litre of gasoline)

Europe and most of the world quote EV consumption as kWh/100 km (lower is better), while US drivers see mi/kWh or kWh/100 mi on the dashboard and MPGe on the EPA window sticker. They are the same quantity in different units, and two of them are inverted (distance per energy versus energy per distance). MPGe uses the EPA's definition that a gallon of gasoline holds the same energy as 33.705 kWh of electricity. Note that dashboard figures exclude charging losses of roughly 10%, while EPA ratings include them.

Worked example

An EV that uses 17 kWh/100 km consumes 170 Wh/km, or 170 × 1.609 = 274 Wh/mi. That is 1,000 ÷ 274 = 3.66 mi/kWh (5.88 km/kWh), 27.4 kWh/100 mi and 33,705 ÷ 274 = 123 MPGe — the energy equivalent of 1.91 L/100 km of gasoline.

Sources: US DOE / EPA fueleconomy.gov — Electric vehicles: MPGe and kWh/100 mi · EPA — Text of the electric vehicle label (33.705 kWh per gallon)

Frequently asked questions

How do I convert kWh/100 km to mi/kWh?

Divide 62.14 by the kWh/100 km figure. For example, 17 kWh/100 km = 62.14 ÷ 17 = 3.66 mi/kWh. Going the other way, kWh/100 km = 62.14 ÷ mi/kWh.

What is MPGe?

Miles per gallon equivalent: the miles an EV drives on 33.705 kWh, the energy content of one US gallon of gasoline as defined by the EPA. A car using 30 kWh/100 mi rates 112 MPGe.

What is good EV efficiency?

Small and aerodynamic EVs manage 13–16 kWh/100 km (4–4.8 mi/kWh) in mild weather; mid-size cars and crossovers 16–20 kWh/100 km; large SUVs and pickups 22–30 kWh/100 km. Highway speed and cold weather raise consumption.

Why does my car show a better figure than the official rating?

The dashboard counts energy taken from the battery, while EPA and WLTP figures are measured at the wall and include charging losses. Expect the wall figure to be about 10–15% higher.

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This calculator is for educational purposes. Double-check important results before acting on them.