Electric car range and efficiency, explained

On a petrol car you look at litres per hundred kilometres. On an EV, the equivalent figure is consumption in kWh per 100 km. Once you understand it, you can work out real range yourself and compare two cars fairly.

Consumption: kWh/100 km

It shows how much energy the car uses to cover 100 km. A compact EV typically uses around 14–18 kWh/100 km in mixed driving, while a large SUV can exceed 20–25 kWh/100 km, especially in winter and on the motorway.

Battery capacity: gross and usable

Manufacturers sometimes quote gross capacity, meaning everything the battery can hold. The car only uses part of it, the usable capacity, keeping a buffer at the bottom and top to protect the cells. For calculations, always use usable capacity.

How to work out range

Range (km) ≈ usable capacity (kWh) ÷ consumption (kWh/100 km) × 100. For example, a 60 kWh usable battery and 16 kWh/100 km gives about 375 km. In winter, at 20 kWh/100 km, the same car manages around 300 km.

Why WLTP range differs from real range

WLTP is the test cycle used in Europe for all new cars since 2018. It is more realistic than the old NEDC, but it is run under controlled conditions, at moderate temperatures and with a large share of urban driving. On the motorway and in winter, real range is usually noticeably lower.

What battery “health” means

State of health (SoH) shows how much capacity is left compared with new. A battery at 90% SoH has about 10% less range than when new. On a used car, measured SoH is one of the most important numbers. See inspecting a used EV.

The factors that change consumption in real life are explained in what affects range.