EV Charging Cost Calculator

Calculate EV charging cost from monthly mileage, vehicle efficiency, home and public electricity tariffs, charger efficiency, and optional petrol comparison.

Last updated 23 April 2026

EV charging cost planner Estimate home EV charging cost, away charging, cost per 100 miles or kilometres, and the petrol break-even point from your own tariff and efficiency assumptions.

Distance unit

Driving and efficiency Monthly mileage (mi) Vehicle efficiency (mi/kWh)

Charging mix and tariffs Home charging (% of miles)

Home electricity tariff (£/kWh) Away/public charging tariff (£/kWh)

Charger efficiency (%) Currency symbol

Petrol comparison and break-even tariff

Petrol price (£/litre) Comparable petrol vehicle (UK MPG)

Estimated charging cost

£103.89

Monthly total for 1,000 mi, with 80% charged at home and the rest at the away/public tariff.

Annual charging cost: £1,246.67/yr
Cost per 100 mi: £10.39
Wall energy per month: 277.78 kWh
Blended cost per mi: £0.104/mi

Home charging	£62.22/mo
Away/public charging	£41.67/mo
Battery energy	250.00 kWh/mo
Charging losses included	27.78 kWh/mo

Tariff scenarios

All miles at home tariff

£77.78/mo

£0.280/kWh - £0.078/mi - Shows what the same mileage costs if every mile is replenished at your home rate.

Half-price off-peak tariff

£38.89/mo

£0.140/kWh - £0.039/mi - Useful for testing whether an overnight EV tariff would materially change running cost.

All miles at away/public tariff

£208.33/mo

£0.750/kWh - £0.208/mi - Shows the penalty if the same mileage is mostly rapid, workplace, or destination charging.

How to read the result The blended cost per mile is the best quick comparison figure. Home charging dominates the saving when your public or rapid charging tariff is much higher than your overnight home rate.

About this calculator

General-reference calculator Reviewed 23 April 2026 Updated 23 April 2026

Editorial responsibility

Calcipedia editorial team

This page is maintained against the site trust model for its topic and updated when formulas, sources, or guidance materially change.

Formula provenance

Formula notes are kept in the page explanation when a named standard or reference materially affects the result.

Methodology

Converts entered monthly distance into miles, divides by the entered EV efficiency to estimate battery-side kWh, divides by charger efficiency to estimate wall-side kWh, then applies home and away/public per-kWh tariffs according to the entered charging mix. The petrol comparison converts annual miles and UK MPG into litres using 4.54609 litres per UK gallon, applies the entered petrol price, and derives an electricity break-even tariff from annual petrol cost divided by annual wall kWh.

Limitations

Assumes the entered tariffs are flat per-kWh prices and does not model time-of-use windows, tiered tariffs, demand charges, standing charges, taxes not included in the entered rate, or network membership pricing
Does not include charger installation, electrical panel upgrades, parking fees, idle fees, public charger session fees, battery degradation, or maintenance costs
Uses one efficiency value for the whole mileage estimate even though real EV efficiency changes with weather, speed, route, tyres, payload, HVAC use, and driving style
Applies one charger-efficiency assumption to both home and away charging, although actual losses can differ by charger type and battery condition
Petrol comparison uses UK imperial MPG and litres; convert US MPG before using that optional comparison
Use the result for budgeting and tariff comparison, not as a guarantee of charger availability, route cost, or future electricity prices

Disclaimer

This EV charging cost calculator is a planning estimate. Confirm tariff-sensitive decisions against your electricity bill, supplier tariff sheet, charging-network prices, and your vehicle's real efficiency data.

Formula notes

Alternative Fuels Data Center - Charging Electric Vehicles at Home — Official DOE/AFDC guidance explaining home EV charging, cost per mile, electricity price per kWh, vehicle efficiency, and time-of-use rate considerations.
US Department of Energy - How To Charge Electric Vehicles — Official DOE consumer guidance on EV charging levels, home and public charging, charging time, and cost considerations.
GOV.UK - Electric vehicles: costs, charging and infrastructure — UK government guidance covering electric vehicle charging costs, infrastructure, home charging, public charging, and off-peak tariff context.
FuelEconomy.gov - Electric vehicles — Official US fuel-economy resource for comparing EV efficiency, range, and fuel-cost information.

Change notes

Change note: this page's updated date changes only when the formula, labels, examples, or user guidance materially changes. Cosmetic or deploy-only edits do not refresh the date.

See our calculation methodology and editorial standards, plus the editorial contact route, for how this estimate is produced and corrected.

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Electric Vehicles

EV charging cost calculator: home, public, per-mile, and petrol comparison

An EV home charging cost calculator estimates the electricity cost of charging an electric vehicle at home from monthly mileage, vehicle efficiency, electricity tariff, and charger efficiency.

How home EV charging cost is calculated

The energy needed at the battery equals miles driven divided by the vehicle's efficiency in miles per kWh. The energy drawn from the wall is slightly higher because of losses in the charger and cable, typically 5-15%. Multiplying wall energy by the electricity unit rate gives the charging cost.

Home charging typically costs significantly less per mile than public rapid charging. Most drivers charge overnight on a standard tariff or a dedicated off-peak EV tariff, which can reduce running costs further.

This calculator keeps the wall-energy step visible because it is the number you actually pay for on the electricity bill. If the car uses 250 kWh at the battery in a month and the charging setup is 90% efficient, the wall draw is about 278 kWh before the tariff is applied.

kWh at battery = Miles / Efficiency (mi/kWh)

Energy consumed by the vehicle for the miles driven.

kWh from wall = kWh at battery / Charger efficiency

Actual electricity drawn, accounting for charger losses.

Charging cost = kWh from wall x Electricity tariff

Total cost in your local currency. This is the specific relationship the calculator applies when building the result.

Cost per mile = Total charging cost / Miles driven

The cleanest running-cost comparison against petrol, diesel, or another EV tariff.

Home, public, and off-peak charging scenarios

A home EV charging cost estimate can be misleading if it silently assumes every mile is charged at one low overnight rate. Many drivers use mostly home charging but still add occasional workplace, destination, or rapid charging. The charging mix matters because public and rapid tariffs can be several times higher than a cheap off-peak home tariff.

The calculator therefore splits mileage into home-charged miles and away-charged miles. It reports the home portion, the away or public portion, and a blended cost per mile so you can see whether the headline monthly number still makes sense for your real charging behaviour.

The tariff scenarios are deliberately simple: all miles at the home rate, all miles at a lower off-peak comparison rate, and all miles at the away/public tariff when you enter one. That makes the impact of switching tariff or relying on rapid chargers clear without pretending to know your supplier's exact time-of-use schedule.

Comparing EV costs to petrol

Petrol running cost depends on fuel price per litre, vehicle MPG, and annual mileage. Dividing annual miles by MPG gives gallons used; multiplying by 4.546 converts UK gallons to litres; multiplying by the pump price gives the annual fuel bill.

At typical UK electricity and petrol prices, EVs cost roughly three to four times less per mile to run at home. However, public rapid charging can approach or exceed petrol costs per mile, so the proportion of home charging matters significantly.

The petrol comparison is most useful as a break-even check. If the calculator says petrol breaks even at a much higher electricity tariff than you actually pay, charging remains cheaper on the entered assumptions. If the break-even tariff is close to your public charging price, the saving depends heavily on how much of your mileage you can charge at home or off peak.

Petrol litres per year = Annual miles / MPG x 4.54609

Uses UK imperial gallons for the MPG comparison input.

Petrol cost per year = Litres per year x Petrol price per litre

Turns the comparable petrol vehicle's annual fuel use into a cost.

Break-even electricity tariff = Petrol annual cost / Annual wall kWh

Shows the per-kWh electricity price where the entered EV and petrol assumptions would cost the same.

Which efficiency number should you enter?

If your car or trip computer reports miles per kWh, enter that directly when the calculator is in miles mode. A higher miles-per-kWh number means the car travels farther on each kWh and will cost less to run at the same tariff.

If your source reports kWh/100km, switch the calculator to kilometres mode and enter the kWh/100km figure. In that format, lower is better because it means the vehicle consumes less energy to travel the same distance.

Use a realistic efficiency figure for the driving you are planning. Cold weather, motorway speed, roof boxes, payload, tyre pressure, heating, air conditioning, and elevation can all move real-world EV efficiency away from the published label figure.

What the result can and cannot tell you

The result is strongest for household budgeting, commute planning, and comparing charging tariffs. The monthly cost, annual cost, cost per mile, and cost per 100 miles are all direct enough to compare with a fuel-cost calculator or an electricity-cost calculator.

It is not a route planner and it does not know real charger availability, idle fees, parking charges, network membership prices, demand charges, or battery preconditioning behaviour. It also treats the entered tariff as a flat per-kWh rate even though real tariffs may vary by time of day or charging network.

For a better real-world estimate, use your latest electricity bill or supplier tariff sheet for the home rate, your EV's recent trip efficiency rather than an optimistic brochure figure, and a public tariff that matches the chargers you actually use.