By moving the slider, tell us how many miles you drive a year to find out typical annual fuel savings if you switch from petrol/diesel to an all-electric car and charge at home, either on a standard variable rate (average Ofgem energy price cap, July to September 2026) or on a typical off-peak EV tariff:

Annual Mileage

I drive 0 Miles per year

£0*

Estimated yearly fuel savings in an electric car

Petrol/Diesel*

£0

Cost estimate per year

£0 / litre

Electric*

£0

Cost estimate per year

26.11p / kWh

Electric with an off peak tariff*

£0

Cost estimate per year

8.5p / kWh

* Fuel savings and costs are estimated and should be considered as guidelines. The calculations are based on the annual mileage you choose above and the following assumptions: a litre of fuel costs £; your petrol/diesel car has an average efficiency of mpg; you charge your electric car at home at p per kWh; your electric car has an average efficiency of miles per kWh.

Want to know more about going electric?

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Electricity and Fuel Cost Per Mile Analysis

Below are typical fuel costs per mile for EVs and standard petrol and diesel cars. The data is based on a distance of 10,000 miles for cost per mile calculations.

We display both the p standard variable tariff rate from our calculator above (applied 24 hours a day), together with an example off-peak home electricity rate of p.

	Cost per Mile	Vehicle Efficiency	Fuel Cost
Electric Car – Off-peak tariff	p	miles per kWh	p per kWh
Electric Car – Standard variable tariff	p	miles per kWh	p per kWh
Diesel Car	p	mpg	£ per litre
Petrol Car	p	mpg	£ per litre

Understanding how much petrol / diesel is per mile illustrates how the electric vs petrol / diesel car comparison favours electric, especially when charging off-peak.

Why Are The Savings So Big?

Our Fuel Cost Calculator summarises how much you can save, on average, when you compare traditional fuel vs electric cars. The secret behind the savings is as follows:

The fuel cost per mile in petrol and diesel cars is high. Why? For two reasons:

Fuel prices at UK pumps are generally quite high.
Internal combustion engine vehicles are not very efficient at converting fuel into forward motion.

By contrast, the fuel cost per mile in an electric car is low if you charge at home. The main reasons for this are:

Standard home electricity prices are protected by Ofgem's Energy Price Cap.
Dedicated tariffs for homes with EVs are available, offering cheaper, off-peak charging.
Electric cars – with their batteries and electric motors – are very efficient at using electricity to make the car go forwards.

What Is Ofgem's Energy Price Cap?

Ofgem’s Energy Price Cap is a limit on the maximum rates energy suppliers can charge households on standard variable tariffs and default tariffs for gas and electricity. It applies to the unit rate you pay for each kWh and the daily standing charge, rather than putting a fixed ceiling on your total bill. That means the more energy you use, the more you pay.

The cap is designed to make sure customers who have not fixed their tariff pay a fairer price that reflects underlying costs such as wholesale energy, network charges, policy costs and VAT. It is reviewed by Ofgem every three months.

The current capped rates for July to September 2026 are for Electricity: 26.11p per kWh and 57.19p daily standing charge; and for Gas: 7.33p per kWh and 29.04p daily standing charge.

What Influences the Cost of Fuel?

Fuel prices at UK pumps can vary due to:

Global crude oil and wholesale fuel prices: which move with supply, demand, refinery capacity, and geopolitical events that affect supply routes.
The pound–dollar exchange rate: oil is priced in US dollars, so a weaker pound typically makes imports more expensive even if crude prices are stable.
UK taxes: fuel duty and VAT are built into the pump price, meaning tax policy can have a major impact on what you pay per litre.
Retail competition and margins: local competition, distribution costs, and retailer pricing behaviour can affect how quickly wholesale price changes show up at the pump.

Fuel Cost Calculator FAQs

Our calculator takes your annual mileage figure and then applies it as follows (assume you drive miles a year):

For electric cars: to cover miles a year, in an EV with average efficiency of miles per kWh, you need units (kWh) of electricity. The maths is: divided by = . Charging at home off-peak at p per kWh will cost you £ a year.

For petrol/diesel cars: we assume an average engine efficiency of mpg and an average fuel price of £ per litre. To cover the same miles, you need litres of fuel which will cost you £ per year.

We use the average of the latest diesel cost per litre and petrol cost per litre nationwide (fuel data sourced from the RAC).

We update our fuel cost calculator at least every month with the latest fuel prices.

For the standard variable rate in the main calculator, we use Ofgem’s official average Energy Price Cap rate. The price cap changes four times a year and is applied quarterly, as follows: January to March, April to June, July to September, and October to December.

For the off-peak rate in the calculator, we use an actual rate from one of the leading home EV tariff providers in the UK.

Some public charging points are still free to use, however most now charge.

Rates typically vary from about 54p per kWh to as much as 79p per kWh for the faster ‘rapid’ or 'ultra-rapid' chargers (source: Zapmap).

If you only use public chargers occasionally – and do most of your charging at home – you will still save a lot of money by switching to electric motoring.

If you do most of your charging at public charging stations, then your savings will be much less and it might even be cheaper in a petrol or diesel car, depending on what kWh rate you pay.

Yes, we update all the fuel and electricity price assumptions once a month. The Fuel Cost Calculator should therefore give you a fairly accurate average savings result, though regional and supplier differences will change the result in specific situations.

Next Steps

If you are considering electric for your next car, get in touch with us now on 0118 3048 688 or email enquiries@selectcarleasing.co.uk

Alternatively, check out our handy EV Guides or browse our latest Electric & Hybrid lease deals below:

Guide

Electric Vehicle Charging Points

If you do get an EV and have off-street parking, you will want to have a dedicated charging point installed. This allows you to charge quickly and safely. Browse our range of EV chargers, all available at excellent prices with nationwide installation.

Guide

Understanding Electric Vehicle Range

Do you have range anxiety? Worried you might not reach your destination in an all-electric car before the battery runs flat? In this detailed guide, we explain the difference between WLTP and real-world range, how to extend range, etc.

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Browse Guides to Electric Motoring

To support our fantastic EV lease deals, we have a wide-ranging set of guides to answer all your electric questions. We cover topics like range, charging, what are BEVs, PHEVs and HEVs, electrifying your fleet, and much more.