Electric vehicles measure their power consumption in kilowatts ( kW) in the same way Petrol and Diesel is measured in litres/ gallons. The cost to charge is very simple determined by multiplying how many kilowatts are used by the rate you pay for your electricity.
Current rates for a kilowatt kW of electric ( Second half of 2025) are approximately as follows*
Domestic off peak Tariff 7.5 pence per kW on average
Domestic standard rate 24 pence per kW on average
Public chargers 75 pence per Kw on average
To keep the maths simple we will make take a broad approximation that electric vehicles use 1 Kw of power ever 4 miles travelled ( large vehicles use more smaller vehicle less and the rate is lower in the winter when lights heaters are on etc ).
Please note the above is a sweeping approximation, t is akin to saying all Petrol and Diesel cars do 40 mpg. Nonetheless the assumption is broadly representative.
To travel 100 miles on this basis requires 250 watts of power are used ( 100 divided by 4 miles).
The approximate cost to travel 100 miles and 1 mile is as shown in the table below based on the rates for electricity per kW shown above.
| Charging Tarriff | kW per 100 miles ** | Approximate price per KW £* | Cost per 100 miles | Cost per mile |
| Home Off Peak | 25 kW | £0.075 | £1.88 | £0.02 |
| Home Standard | 25 kW | £0.24 | £6.00 | £0.06 |
| Public charging | 25 kW | £0.75 | £18.75 | £0.19 |
As can be seen the cost to charge at home in particular is favourable compared to Petrol and Diesel which typically cost around 10 to 20 pence per mile for the fuel used. If you have a pug in hybrid your are better off depleting the electric before switching to the Petrol/ Diesel
- *Check with your energy / utility provider or public charger provider for more accurate rates.
- **Electric consumption varies from vehicle to vehicle.
