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, January to March 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

27.69p / kWh

Electric with an off peak tariff*

£0

Cost estimate per year

9.5p / kWh

Want to know more about going electric?

Phone us now on 0118 3048 688

or email one of our expert leasing consultants at enquiries@selectcarleasing.co.uk

Electricity and Fuel Cost Per Mile Analysis

Below are typical fuel costs per mile for EVs and standard petrol and diesel cars.

We display both the current standard variable rate from our calculator above, together with an example off-peak home electricity rate of 9.5p per kWh (available at time of writing on 10 March 2026).

	Cost per Mile	Vehicle Efficiency	Fuel Cost
Electric Car – Off-Peak Tariff	2.4p	4 miles per kWh	9.5p per kWh
Electric Car – Standard Variable Tariff	6.9p	4 miles per kWh	27.69p per kWh
Diesel Car	16.0p	43 mpg	150.97p per litre
Petrol Car	17.4p	36 mpg	137.51p 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 January to March 2026 are for Electricity: 27.69p per kWh and 54.75p daily standing charge; and for Gas: 5.93p per kWh and 35.09p daily standing charge.

Fuel Cost Calculator FAQs

Our calculator takes your annual mileage figure and then applies it as follows (assume you drive 7,000 miles a year):

For electric cars: to cover 7,000 miles a year, in an EV with average efficiency of 4 miles per kWh, you need 1,750 units (kWh) of electricity. The maths is: 7,000 divided by 4 = 1,750. Charging at home off-peak at 9.5p per kWh, for example, will therefore cost you £166.25 a year.

For petrol/diesel cars: we assume an average engine efficiency of 39.5 mpg and an average fuel price of £1.4424 per litre. To cover the same 7,000 miles, it will cost you approximately £1,162.05 per year in fuel.

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 77p per kWh for the faster '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.

Guide

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.