How long does it take to charge an electric car?

The maths

Charging time is the energy you need divided by the charger’s power:

time (hours) = energy to add (kWh) ÷ power (kW)

Power is volts times amps. A UK socket supplies about 230V. A 3-pin socket is limited to 10A for car charging, which gives 10 × 230 = 2,300W, or 2.3kW. The RAC says most manufacturers limit the current to “10A or less, which equates to a maximum of 2.3kW”. A home wall charger sold as 7kW runs at up to 32A, so 32 × 230 = 7,360W, which charger specifications round to 7.4kW. The RAC calls that roughly three times the power and speed of a domestic socket.

An 11kW or 22kW charger needs a three-phase supply. A home without one must pay for an upgrade: £1,500 to £5,370 on our data (SP Electricity North West publishes an average of £5,370). Ohme’s UK Home Pro, for example, is single-phase only, at 32A and 230V.

Charging time by battery size

Treat each time as a minimum. At 0.301 kWh a mile (EV Database’s average), the four batteries are good for about 133, 199, 256 and 332 miles on paper.

Three things stretch real sessions:

• Losses. ADAC measured five cars and reported that a 2.3kW household socket wasted 12.7% to 24.2% of the electricity drawn and an 11kW wallbox 5.1% to 7% (reported by The Next Web, 19 August 2026). None was measured at 7kW. At a 12.7% to 24.2% loss, a 60 kWh battery on a 3-pin socket takes about 30 to 34 hours rather than 26. If a wall charger lost 7%, as ADAC found at 11kW, a 60 kWh battery would take about 8 hours 43 minutes rather than 8 hours 7 minutes.
• The car’s onboard charger. It caps AC charging whatever the wall charger offers. Which? says it is likely to be 7kW to 11kW, or less for plug-in hybrids. Check your handbook.
• Taper. Cars slow down as the battery fills, so the last few per cent take longer than the arithmetic says.

For a real-world cross-check, Which? lists 38.5 hours on a 2.4kW plug and 12 hours on a 7kW charger for a 2022 Tesla Model Y.

How much does one night give you?

Smart tariffs give you a cheap window of five to seven hours. The energy that fits in it is hours times kW, and the miles follow at 0.301 kWh a mile.

On Intelligent Octopus Go, six hours at 7.4kW is 6 × 7.4 = 44.4 kWh, or 44.4 ÷ 0.301 = 148 miles. At a nominal 7kW it is 42 kWh and about 140 miles. That is a lot of headroom. The DfT average battery-electric car in England covers 9,400 miles a year, which is 25.8 miles a day, or 7.75 kWh. That is about an hour on a 7.4kW charger and about 3 hours 20 minutes on a 3-pin socket, so either fits any of these windows.

The window matters when the charger is slow, the battery is big or you drive far. Octopus says over 80% of charging sessions take under six hours, and that on Intelligent Octopus Go charging beyond six hours a day reverts to the day rate. Our Intelligent Octopus Go guide explains the cap. Some windows are stated in GMT (UW, Ecotricity and ScottishPower), which means 01:00 to 06:00 on the clock in British Summer Time.

Tips to charge faster, or at least on time

• Fit a dedicated wall charger rather than relying on a 3-pin socket. A 7.4kW charger is roughly three times faster, and Electrical Safety First says the extended load and duration of EV charging are likely to exceed what a standard socket-outlet can handle. If you must use a socket, it advises ones marked BS1363/EV on a dedicated circuit.
• Check what the car accepts before paying for more power. A faster wall charger cannot beat the onboard charger. 22kW is only useful with a three-phase supply and a car that takes it, and for most homes it is not worth the supply upgrade. See our 7kW or 22kW guide.
• Top up little and often. The cost and time scale with the energy added. Octopus’s own advice is to treat the car “like you’re sipping a nice drink, not downing it in one go”: keep it plugged in and let it charge in shorter bursts.
• Set your target to what you need. On a smart tariff, a higher target than you will use adds hours and can push charging past the cheap allowance.
• Match the window to the power. At 2.3kW, EDF’s seven hours gives about 53 miles against 38 in five hours. If you are on a slow charger, window length is worth more than a lower rate.
• Know what each hour costs. One hour at 7.4kW is 7.4 kWh, which costs about 56p at Intelligent Octopus Go’s 7.6p and £1.95 at the 26.32p price-cap rate. Our charging cost calculator and the cost-to-charge guide do the sums for your car.

If a charger is slow and you have no driveway, see charging without a driveway.