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EV charging cost calculator

Work out the cost of a charge from the energy added, the price per kWh and charging efficiency. Add a fixed session fee if your public charger charges one. The estimate works in pence, cents, euros, Swiss francs, yen, rupees, won or Australian dollars per kWh.

The key distinction: energy added to the battery is not the same as energy purchased from the grid. Charging losses are included explicitly.

Use your own tariff

There is no single national electricity price, and public charging prices vary by network, speed, membership and time. This page does not publish a current tariff.

Calculate a charge

Your inputs

Changing market resets the example values to the correct price and consumption units.

How do you want to enter the energy?
kWh

This is battery-side energy, before charging losses.

p/kWh

Use pence per kWh, for example 25. Home and public tariffs differ.

%

The share of grid energy that reaches the battery. 90% means 10% is lost.

£

A fixed fee per charging session, not a per-kWh charge.

mi/kWh

Use a dashboard/trip-meter figure based on battery energy. EPA MPGe-derived figures already include charging losses, so do not add them twice.

ExampleExample values are illustrative, not current tariffs. Use your own home, public or time-of-use price.

Estimated result

Charging cost estimate

Estimated charging cost

£11.11

Electricity £11.11 + session fee £0.00. Energy purchased from the grid: 44.44 kWh.

Energy added to battery

40 kWh

Grid energy purchased

44.44 kWh

4.44 kWh lost in charging

All-in cost per grid kWh

£0.25

Includes the session fee

Electricity cost per kWh

£0.25

Excludes the session fee

Cost per mile

£0.079

Estimated range from this charge: 140 mi

Cost per 100 km

£4.93

This is not a quote. Public charging can include idle fees, parking, membership discounts or per-minute billing that are not modelled here. Home charging may have standing charges and time-of-use rates.

The formula

From energy added

grid energy = battery energy ÷ efficiency
electricity cost = grid energy × price per kWh
total cost = electricity cost + session fee

Efficiency is entered as a percentage. At 90%, 45 kWh added to the battery requires 50 kWh from the grid.

From battery percentage

battery energy = capacity × (end SOC − start SOC) ÷ 100
grid energy = battery energy ÷ efficiency

Usable battery capacity is the relevant figure. A 75 kWh pack charged from 20% to 80% adds 45 kWh before losses.

Cost per mile or per 100 km is calculated only when you provide vehicle efficiency. It uses the battery energy and the all-in cost, so a session fee is spread across the estimated range from that charge.

Worked examples

Illustrative energy prices and efficiencies, not current tariffs.

UK home-style

75 kWh · 20→80% · 25p/kWh · 90%

£12.50

50 kWh from grid · £0.079/mile

US public-style

40 kWh · 17¢/kWh · 90% · $2 fee

US$9.56

44.44 kWh from grid · US$0.068/mile

EU example

50 kWh · 10→60% · €0.35/kWh · 88%

€9.94

28.41 kWh from grid · €6.76/100 km

Home, public and lost energy

Home charging

A domestic tariff normally has a unit rate and may have a standing charge, time-of-use bands and taxes. This calculator uses only the unit rate you enter; it does not add standing charges.

Public charging

Networks may bill per kWh, per minute, by session, by membership or by a combination. Only a fixed session fee and a per-kWh price are modelled. Idle and parking fees are excluded.

AC and DC losses

Some energy is lost in the onboard charger, cable, conversion and battery thermal management. The real figure varies with equipment, temperature, state of charge and charging speed.

What is not included

Installation of a home charger, hardware, subscription fees, road tax, insurance, maintenance and depreciation are ownership costs, not charging costs. They are not part of this estimate.

Questions

How much does it cost to charge an EV at home?
Multiply the grid energy needed by your domestic unit rate, then add any fixed charges you want to include. There is no universal answer: the battery size, amount charged, efficiency and tariff all matter. Enter your own pence, cents, euros or Swiss francs per kWh above.
How much does it cost to charge a Tesla at home?
The same formula applies to any EV. Use the usable capacity of the specific model and the percentage you need to add. This site does not publish brand-specific battery sizes or tariffs because they vary by model, market and model year.
Is it cheaper to charge at home or in public?
Often, but not always. Compare the all-in home tariff with the public charger’s per-kWh price, session fee, parking cost and membership. A low headline public rate can be worse once fees are included, and a home tariff can have time-of-use bands.
How long does it take to charge an EV?
Charging time is approximately energy needed divided by average charging power, with losses and tapering. This page calculates cost, not time. Charger power, the vehicle’s acceptance rate and the charging curve all affect duration.
Why is grid energy higher than battery energy?
Charging is not perfectly efficient. The difference is the energy lost as heat and overhead during the charge. At 90% efficiency, 50 kWh from the grid delivers about 45 kWh to the battery.

Sources

Use these for tariff context and efficiency background, not as a live price for your charger.

Page last reviewed: . Formulas are covered by automated tests. Prices are inputs, not live data.

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