EV charging cost calculator
Work out how much a home or public EV charge will cost, from your battery size, the charge range and your electricity price.
Result
Cost
Energy added
Result
Charge level you can afford
How to use this tool
- Enter your battery's usable capacity.
- Set the charge-from and charge-to percentages.
- Enter your electricity price per kWh (your home tariff, or the public charger's advertised rate).
- Read the energy added and the cost.
Assumptions
- Does not include charging losses (energy lost as heat) — real-world energy drawn from the wall is typically 5–15% higher than energy added to the battery.
- Uses a flat price per kWh; does not model time-of-use tariffs or rapid-charger session/connection fees.
Sources & reference data
Technical details: what the fields mean
- Battery capacity
batteryCapacityKwh - Your EV's usable battery capacity, in kWh — check your vehicle's spec sheet.
- Charge from
chargeFromPercent - Battery level before charging starts.
- Charge to
chargeToPercent - Battery level you're charging up to.
- Electricity price
pricePerKwh - Price per kWh — your home electricity tariff, or the public charger's rate (these can be very different).
Methodology
Energy added = capacity × (to% − from%) ÷ 100. Cost = energy added × price per kWh.
Worked example
60kWh battery, 20% → 80%, 30p/kWh home tariff
Inputs: Battery capacity: 60 kWh, Charge from: 20%, Charge to: 80%, Electricity price: £0.30/kWh
Result: 36.0 kWh added, £10.80
Same charge, allowing for ~10% charging losses
Inputs: Battery capacity: 60 kWh, Charge from: 20%, Charge to: 80%, Electricity price: 0.333 (£0.30 ÷ 0.9)
Result: £11.99 (≈ £12) — dividing your tariff by an assumed charging efficiency (0.9 here) is a quick way to include losses without a separate input. 0.9 is illustrative; measured efficiency varies by car, charger and temperature.
Same 36 kWh from an illustrative £0.79/kWh public rapid charger
Inputs: Battery capacity: 60 kWh, Charge from: 20%, Charge to: 80%, Electricity price: £0.79/kWh
Result: £28.44 — over 2.5× the home figure. The £0.79 rate is an example only; check the operator's live price and any session fee.
Practical guidance
- Home overnight tariffs are usually far cheaper than public rapid chargers — compare both before assuming a cost.
- Public rapid/ultra-rapid chargers often price per kWh higher than home electricity, sometimes with an added session fee.
Common mistakes
- Using your home electricity rate to estimate a public rapid-charging cost, which is usually priced separately and higher.
- Ignoring charging losses when comparing to a home energy bill.
FAQs
How much does it cost to charge an EV from 20% to 80%?
For a 60kWh battery at 30p/kWh, about £10.80. Enter your own battery size and price above for an exact figure.
Does this include charging losses?
No — it calculates energy added to the battery. Actual electricity drawn from the wall is typically 5–15% higher. To include losses, divide your price by your assumed efficiency (e.g. 0.30 ÷ 0.9) before entering it.
Where do I find my home electricity price per kWh?
On your bill or in your supplier account as the unit rate. If you're on a time-of-use EV tariff, use the off-peak rate for overnight charging. Ofgem publishes the current price-cap unit rates for standard variable tariffs as a reference point.
I have a fixed budget — how much charge can I afford?
Use reverse mode below: enter your budget, battery size, starting charge and price to see the charge level you can reach.
Last reviewed: 2026-09-24
Does not account for charging losses, time-of-use tariffs, or public-charger session fees.
This tool provides an indicative estimate, based on the assumptions stated above.
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