EV charging cost calculator UK
Calculate how much it costs to charge your electric car at home using your usable battery capacity, electricity unit rate, charging efficiency and normal charge range.
Enter your charging details
Use the electricity rate from your own tariff where possible. The default is the current Great Britain Ofgem benchmark.
Simple off-peak comparison
This shows what the same charging routine would cost if every session could take place entirely at the off-peak rate entered above.
Want to understand what affects the cost?
See battery-size examples, charging losses, monthly costs, standing charges and off-peak charging explained.
How the EV charging cost calculator works
The calculator first works out how much usable battery energy must be added between your starting and target charge levels. It then allows for charging losses to estimate the amount of electricity drawn from the home supply.
usable battery capacity × percentage being charged
battery energy added ÷ charging efficiency
electricity drawn × electricity unit rate
cost per session × similar sessions per week × 52
Worked example
A 60kWh usable battery charged from 20% to 80% needs 36kWh added to the battery.
At 90% charging efficiency, approximately 40kWh must be drawn from the electricity supply.
At 26.11p/kWh:
40 × £0.2611 = approximately £10.44.
If an equivalent charging session happens three times per week, that works out at roughly £136 per month or £1,629 per year.
Why charging efficiency matters
Not every kilowatt-hour taken from the electricity supply ends up stored in the vehicle battery. Energy can be used by charging electronics, battery thermal management and other supporting systems or lost as heat.
The calculator therefore defaults to a 90% AC charging-efficiency assumption but also allows 85% and 95% scenarios.
What the off-peak comparison does — and does not do
The off-peak result is intentionally simple. It takes exactly the same battery, charge range, charging efficiency and weekly charging frequency and applies the alternative unit rate you entered.
It does not attempt to model your entire household electricity tariff.
What is not included?
The calculator estimates electricity used for home EV charging. It does not include:
- the cost of buying an EV charger
- charger installation cost
- public charging prices
- vehicle finance or depreciation
- the household standing charge in the per-charge result
- solar generation unless you manually reflect it in the rate entered
Important limitations
Results are estimates rather than electricity-bill predictions. Actual energy use can vary with the vehicle, temperature, battery-management systems, charger, charging power and other conditions.
The monthly and annual figures assume that the number of similar charging sessions you enter is reasonably representative of your routine.
Charging time or charging cost?
Charger power mainly affects how quickly an EV charges. This tool concentrates on the electricity cost.
EV charging cost calculator FAQs
How do I calculate the cost of charging an EV?
Calculate the electricity drawn from the grid and multiply it by your electricity unit rate. This calculator also allows for charging losses.
What electricity rate should I enter?
Use the unit rate from your own electricity tariff wherever possible. The Ofgem figure used as the default is only a Great Britain average benchmark.
Does the calculator include charging losses?
Yes. It defaults to 90% charging efficiency and allows you to select 85% or 95% instead.
Does the calculator include the electricity standing charge?
No. The standing charge is normally payable whether the EV is charged or not, so it is excluded from the additional electricity cost of an individual charging session.
Can I compare an off-peak EV tariff?
Yes. Enter an off-peak unit rate for a simple comparison. For a whole-home tariff comparison including peak electricity and standing charges, use the Smart EV Tariff Savings Calculator.
Does a faster charger make electricity more expensive?
Charger power primarily affects charging time. Electricity cost is mainly determined by the amount of energy drawn and the tariff rate, although charging losses can vary under different conditions.
How much does it cost to charge an electric car at home in the UK?
The cost of home EV charging depends mainly on how much electricity the car needs, your electricity unit rate and the amount of energy lost during charging. The calculator above uses your own rate and includes an adjustable charging-efficiency assumption.
As a current benchmark, the Ofgem average standard-variable electricity rate for customers paying by Direct Debit in England, Scotland and Wales is 26.11p/kWh for 1 July to 30 September 2026. Actual rates vary by region, tariff and payment method, so your own electricity bill is the best figure to enter.
Battery energy needed = battery size × percentage added.
Grid electricity needed = battery energy needed ÷ charging efficiency.
Cost = grid electricity needed × electricity rate.
For example, a 60 kWh battery charged from 20% to 80% needs 36 kWh stored in the battery. At 90% charging efficiency, approximately 40 kWh must be drawn from the grid. At 26.11p/kWh, that costs about £10.44 per charge.
Example home charging costs
| Electricity rate | Cost per charge* | Annual cost* | Saving vs 26.11p |
|---|---|---|---|
| 26.11p/kWh | £10.44 | ~£1,629 | — |
| 15p/kWh | £6.00 | ~£936 | ~£693 |
| 10p/kWh | £4.00 | ~£624 | ~£1,005 |
| 8p/kWh | £3.20 | ~£499 | ~£1,130 |
*Example assumes a 60 kWh battery charged from 20% to 80%, three times per week, at 90% charging efficiency. It assumes every charge is bought at the stated unit rate. Standing charges are excluded.
Why does charging efficiency matter?
The amount of electricity shown on the vehicle’s battery display is not necessarily the same as the amount drawn from your electricity meter. Some energy is used by the onboard charger, battery management and thermal systems or is lost as heat. That is why this calculator separates battery energy from grid electricity.
A 90% efficiency assumption means that putting 36 kWh into the battery requires around 40 kWh from the grid. The calculator lets you test 85%, 90% and 95% assumptions because real-world charging efficiency varies.
Are off-peak EV tariffs worth comparing?
They can be, particularly if most of your EV charging can take place during a cheaper overnight or smart-charging window. However, tariff structures differ. Some have fixed off-peak windows, some schedule charging automatically, and some have eligibility or equipment requirements.
Instead of assuming that one named tariff is always cheapest, enter the current off-peak rate offered by your supplier into the calculator. This also makes it easier to compare tariffs when prices change.
How does home charging compare with public charging?
Public charging is normally priced separately from your domestic electricity tariff, so the home electricity rate used by this calculator should not be used to estimate the price of a public rapid charging session. Public prices vary by network, location, charger speed, membership and payment method.
Does a home wallbox make financial sense?
A home chargepoint can offer faster and more convenient charging than a standard socket and may make it easier to use time-of-use electricity tariffs. Whether it pays for itself depends on installation cost, your mileage, your existing charging options and the tariff you use.
Government grant eligibility also depends on the type of property and parking arrangement, so do not assume every homeowner automatically qualifies for a chargepoint grant.
Frequently asked questions
How much does it cost to fully charge an electric car at home?
It depends on battery size, electricity price and charging losses. Using an illustrative rate of 26.11p/kWh and 90% charging efficiency, charging from 0% to 100% would use approximately 44.4 kWh from the grid for a 40 kWh battery and cost about £11.60. A 57.5 kWh battery would use around 63.9 kWh from the grid and cost about £16.68, while an 82 kWh battery would use around 91.1 kWh and cost about £23.79. Enter your own electricity rate above for a personalised estimate.
What is the cheapest time to charge an electric car at home?
That depends entirely on your electricity tariff. Some tariffs offer a fixed overnight off-peak window, while others use smart charging and schedule the vehicle during cheaper periods. Check the current terms of your tariff and enter its off-peak unit rate into the comparison field above.
Do I need a special EV electricity tariff?
No. An EV can be charged using an ordinary domestic electricity tariff. An EV or time-of-use tariff may reduce charging costs if it offers a lower rate at times when you can regularly charge the vehicle. Whether it saves money overall depends on both the peak and off-peak rates and how your household uses electricity.
How much does it cost to charge an EV per mile?
Cost per mile depends on the vehicle’s efficiency as well as the electricity rate. For example, an EV averaging 3.8 miles per kWh at the battery and charging at 90% efficiency uses about 0.29 kWh of grid electricity per mile. At 26.11p/kWh that is around 7.6p per mile. At an 8p/kWh off-peak rate it is around 2.3p per mile. Actual efficiency varies by vehicle, speed, temperature and driving conditions.
Does charging an EV increase your electricity bill significantly?
It increases electricity consumption, but the amount depends on how far you drive, how efficient the vehicle is, how much energy is lost during charging and the tariff used. The calculator above estimates the additional charging electricity cost separately from your normal household consumption.
Can I use my existing electricity tariff to charge my EV?
Yes. You do not need a dedicated EV tariff to charge an electric car at home. Enter the unit rate shown on your electricity bill into the calculator to estimate the cost on your existing tariff, then use the off-peak comparison field if you want to compare it with another rate.
What charging efficiency should I use?
The calculator defaults to 90% as a practical AC charging estimate. Selecting 85% models higher charging losses, while 95% models lower losses. Real efficiency varies with the vehicle, charger, temperature, battery state and supporting systems, so the result should be treated as an estimate rather than a meter reading.
Does the calculator include the electricity standing charge?
No. The calculator estimates the extra electricity used to charge the EV. A household standing charge is normally payable whether or not you charge a vehicle, so including it in every EV charging session would overstate the additional cost caused by the car.