EV Cost Per 100 km Calculator
Reviewed by Edward, publisher and site editor ยท
Calculate the electricity cost of driving an electric car 100 kilometres after factoring in charging losses. Enter your car's consumption in kWh per 100 km, your electricity price per kWh and your charging efficiency, and the calculator returns cost per 100 km, cost per km, monthly cost and annual cost.
The cost per 100 km metric is the electric equivalent of L per 100 km for petrol cars. It is the cleanest way to compare running costs between vehicles, between tariffs and between home and public charging.
Formula for EV cost per 100 km
Cost per 100 km equals consumption in kWh per 100 km multiplied by electricity price per kWh, divided by charging efficiency expressed as a fraction. Cost per km is that figure divided by 100. Monthly cost is cost per km multiplied by monthly distance. Annual cost is monthly cost multiplied by 12.
Typical consumption ranges
Efficient compact EVs use 12 to 15 kWh per 100 km. Mainstream long-range sedans and crossovers sit between 16 and 20 kWh per 100 km. Larger electric SUVs and pickups at motorway speed can exceed 22 to 28 kWh per 100 km, especially in cold weather or with roof boxes fitted.
Why charging efficiency matters
Cost per 100 km calculated against battery energy understates the true bill because not every kilowatt-hour pulled from the wall reaches the battery. Dividing by charging efficiency converts battery energy into wall energy, which is what your utility bills you for. A 90 percent assumption is a sensible default for home wallbox charging.
How home and public charging change the result
The same car at the same consumption can cost very different amounts per 100 km. At 0.20 per kWh on home electricity and 90 percent efficiency, a 17 kWh per 100 km EV costs about 3.78 per 100 km. At 0.65 per kWh on a public DC charger and 92 percent efficiency, the same car costs about 12.01 per 100 km โ more than three times higher.
EV vs petrol cost per 100 km
A typical petrol car at 6.5 L per 100 km and 1.70 per litre costs 11.05 per 100 km. An equivalent EV at 17 kWh per 100 km, 0.25 per kWh and 90 percent efficiency costs 4.72 per 100 km โ about 57 percent less. The advantage shrinks on expensive public charging and grows on off-peak tariffs.
Common questions
How do I calculate EV cost per 100 km?
Multiply consumption in kWh per 100 km by the electricity price, then divide by charging efficiency. At 0.25 per kWh, 18 kWh per 100 km and 90 percent efficiency, the result is 5.00 per 100 km.
How many kWh does an EV use per 100 km?
Efficient compact EVs can use around 12 to 15 kWh per 100 km, while many mid-size EVs fall around 16 to 20. Larger SUVs and high-speed motorway driving can be higher.
Why does charging efficiency affect the result?
Your meter records the electricity drawn from the wall, and some of that energy is lost before it reaches the battery. Accounting for those losses gives a more realistic bill estimate.
Why might my real-world cost be higher?
Cold weather, motorway speeds, tyres, hills, cabin heating and public-charging fees can all increase what you actually spend. Use your own tariff and normal consumption for the best estimate.