How much does it cost to charge an electric car at home?

The formula

Charging cost is energy times price:

cost (£) = kWh × price in pence ÷ 100

To get a cost per mile, replace kWh with the car’s consumption. The average full-electric car uses 0.301 kWh a mile, or 3.32 miles per kWh, according to EV Database’s average of its listed models. Octopus uses the same figure. So:

pence per mile = rate (p/kWh) × 0.301

At Intelligent Octopus Go’s 7.6p, that is 7.6 × 0.301 = 2.29p a mile. At the 26.32p price-cap rate it is 26.32 × 0.301 = 7.92p. The average is only an average: other sources assume anything from 3.3 to 4.5 miles per kWh, and your car and driving style will move it.

What a full charge costs, by battery size

The table multiplies each battery’s capacity by the rate. Each cell shows the sum, such as 60 kWh × 7.6p. The miles under each battery size are the paper range at 0.301 kWh a mile, so real range will differ.

A worked example for a 60 kWh battery on Intelligent Octopus Go: 60 kWh × 7.6p = 456p, which is £4.56. On the price cap: 60 × 26.32p = 1,579p, which is £15.79. At a public rapid charger: 60 × 79p = £47.40.

Most charging is a top-up, not a fill from empty. The cost scales with the energy you add, so putting 40 kWh into a 77 kWh battery costs 40 × 7.6p = £3.04 on Intelligent Octopus Go.

Cost per mile, per 100 miles and per year

Intelligent Octopus Go’s figure ties to Octopus’s own claim: 7,000 miles × 0.301 kWh × £0.076 = £160.13. Home off-peak is about 10 times cheaper per mile than a public rapid charger (23.78 ÷ 2.29 = 10.4) and 3.5 times cheaper than the capped standard rate.

Work it out for your own car

The calculator uses the same inputs. Move the sliders for your mileage, your car’s efficiency and the petrol car you would compare with.

For a standalone version, see the charging cost calculator.

Home, public or petrol

Zapmap’s September 2026 index puts the average pay-as-you-go price at 54p/kWh for standard chargers (3 to 49kW) and 79p for rapid and ultra-rapid chargers (50kW and above), both about 4% up on a year ago. At 0.301 kWh a mile that is 16.25p and 23.78p a mile.

Unleaded was 174.88p a litre on 5 October 2026, up from 131.71p on 23 February and 134.76p a year earlier, according to DESNZ. At 40 mpg (RAC’s modelling assumption) that is 19.88p a mile. At 35 to 50 mpg it is 22.7p to 15.9p. So:

• Home off-peak is about a tenth of petrol.
• Public standard charging is cheaper than petrol.
• Public rapid charging is about 20% dearer than petrol at 40 mpg (23.78 ÷ 19.88 = 1.20).

Public charging cannot use the zero VAT rate that applies to home electricity: HMRC says public chargepoint electricity is always standard-rated. Memberships, Tesla’s own network (an average 48p for Tesla drivers, 69p open to all) and promotions can bring prices down. If you cannot charge at home, see our guide to charging without a driveway.

Standing charges and the bit the per-mile figure leaves out

Per-mile figures cover the electricity the car uses. They leave out two things.

Standing charges. The Ofgem cap’s standing charge is 54.83p a day, about £200 a year, and you pay it whether or not you own a car. Switching to an EV tariff does not remove it: Intelligent Octopus Go’s averages 54.34p.

The day rate on the rest of your house. EV tariffs charge more by day than the price cap. Intelligent Octopus Go’s day rate averages 36.70p against 26.32p. Take a home using 2,500 kWh and a car covering 9,400 miles (2,829 kWh):

• Standard tariff at the cap: 5,329 kWh × 26.32p plus 365 × 54.83p is about £1,603 a year.
• Intelligent Octopus Go: 2,500 × 36.70p, plus 2,829 × 7.6p, plus 365 × 54.34p is about £1,331, a £272 saving.
• The same, with 30% of house use moved into the night window: about £1,113.

Below roughly 4,570 miles a year, with no household use shifted, the higher day rate costs more than the car saves. Our EV tariff comparison shows other tariffs, and Intelligent Octopus Go has its own page.

If you have solar panels

Electricity from your own panels costs nothing to use. But a kWh the car takes is a kWh you do not export, so its real cost is the export payment you forgo. Under the Smart Export Guarantee, Ofgem says rates “must always be above zero” and each supplier sets its own, so check yours. Octopus bills Intelligent Octopus Go customers only for what the smart meter imports, and advises letting surplus solar export rather than diverting it to the car. Our solar EV charging guide works through the comparison.

What changes when VAT returns in April 2027

Domestic electricity in Great Britain is zero-rated for VAT from 1 October 2026 to 31 March 2027. If it returns to 5% on the same pre-VAT prices, every home figure above rises 5%. That is our derivation. Intelligent Octopus Go moves from 2.29p to 2.40p a mile and a 9,400-mile year from about £215 to about £226. The price-cap rate moves from 7.92p to 8.32p a mile, about £745 to £782 a year. Public charging is already at 20%, and the Ofgem cap for January to March 2027 had not been published on 10 October.

Our how long to charge guide covers the time side of the same sums.