How much does an electric car cost per mile?
The 'fuel' costs for an electric vehicle are as variable as their petrol or diesel counterparts, and a long range doesn't always tell the full story. Discover how much it costs to charge and drive an EV.
The way we use electric vehicles is changing, and range anxiety is fading fast. With new models often offering more than 200 miles on a full charge, energy efficiency is becoming an increasingly important differentiator. This can have a significant influence on running and electric car charging costs. And a longer range doesn't necessarily reflect better economy.
How much does it cost to charge an electric car?
The cost of charging an electric car varies from model to model. Electricity usage is measured and billed in kilowatt-hours (kWh). Similar to filling with litres of liquid fuel, the more kilowatt-hours a battery can store, the further it will take you and the higher electric car charging cost for a full battery.
It's like fitting a larger fuel tank to a petrol or diesel car, and just as dependent on the 'fuel' costs where you fill up. Using the range, battery capacity and energy price can provide a rough indication of 'fuel' costs per mile.
How far can a kilowatt-hour take an electric car?
It depends on the vehicle. A tougher efficiency test - the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) - was introduced for new vehicles in 2017. This includes four test cycles simulating different road types, where vehicles are fully charged before and afterwards to measure the energy used.
Efficiency data is presented as a weighted 'combined' average, commonly in watt-hours per kilometre (Wh/km). However, some list kilowatt-hours per 100 kilometres (kWh/100km), and miles per kilowatt-hour (MPkWh). As UK motorists are used to economy in miles per gallon, MPkWh is perhaps the most relatable of those figures. It's also easy to calculate:
To convert Wh/km to MPkWh:
- Divide the Wh/km figure by 10 to convert it to kWh/100km (if necessary)
- Divide the result by 62 to get kWh/mile (100km is 62 miles)
- Divide 1 by that result to get a figure in MPkWhNo text in field
For example, to work out an Audi e-tron consuming 234Wh/km:
- 234 / 10 = 23.4kWh/100km
- 23.4 / 62 = 0.377kWh/mile
- 1 / 0.377 = 2.6MPkWh
This also provides the most accurate basis for cost-per mile calculations. WLTP figures include the energy lost while charging , and this is paid for regardless of whether it reaches the battery. Most manufacturers also publish vehicles' gross battery capacity, which includes a share that cannot be charged or discharged.
For example, in the Audi e-tron 86.5kWh (91%) of the 95kWh gross capacity is usable . The remainder doesn't contribute to the range or electric car charging cost, and its scale varies between vehicles.
How to calculate EV cost per mile
To work out the cost per mile to drive an electric car, divide the electricity cost (pence per kWh) by the distance it will take you (MPkWh).
Figures for the most popular electric vehicles in the UK (based on SMMT data) are provided below. Calculations are based on average electricity costs for 2021, supplied by the Department of Business, Energy and Industrial Strategy .
It’s worth noting that BEIS data doesn’t include the effects of the latest Ofgem Energy Price Cap, which was introduced at the start of April 2022 . To find out more, read our guide: How will rising energy prices affect electric vehicle drivers?
How do electric vehicle fuel costs per mile compare to petrol and diesel?
HM Revenue and Customs (HMRC) issues Advisory Fuel Rates (AFRs) for travel reimbursement, based on combined cycle economy data for fleet-registered vehicles and fuel prices from the AA .
For fair comparison with the table above, the following calculations do not include the 15% adjustment for ‘real-world’ conditions. However, ‘fuel’ electric vehicle costs per mile are still two to four times lower than their petrol or diesel equivalents.
For additional details around electric car costs per mile and cost comparison information covering electric versus petrol or diesel vehicles, please speak to your LeasePlan Account Manager who will be happy to assist.
 VDA (n.d.). Global WLTP roll-out for more realistic results in fuel consumption. [online] Available at: https://www.vda.de/en/topics/environment-and-climate/Global-WLTP-roll-out-for-more-realistic-results-in-fuel-consumption/WLTP-How-are-plug-in-hybrids-and-electric-cars-measured.html [Accessed 29 Mar. 2022].
 Audi MediaCenter. (2020). Audi e-tron models with high charging performance. [online] Available at: https://www.audi-mediacenter.com/en/press-releases/audi-e-tron-models-with-high-charging-performance-12758 [Accessed 29 Mar. 2022].
 Department for Business, Energy & Industrial Strategy. (2021). Average unit costs and fixed costs for electricity for UK regions (QEP 2.2.4)[online] Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/973052/table_224.xlsx [Accessed 29 Mar. 2022].
 Ofgem. (2022). Price cap to increase by £693 from April. [online] Available at: https://www.ofgem.gov.uk/publications/price-cap-increase-ps693-april [Accessed 29 Mar. 2022].
 HM Revenue and Customs. (2021). Advisory fuel rates. [online] Available at: https://www.gov.uk/guidance/advisory-fuel-rates. [Accessed 24 Nov 2021]