How much does it cost to charge an EV on an Octopus tariff?
The two-line formula for any car and any tariff, a worked example for a typical driver, and how home charging on an EV tariff compares with the alternatives.
Tariff facts, checked 28 October 2026
| Intelligent Octopus Go | EV tariff with smart charging |
|---|---|
| Cheap rate | From 7.9p/kWh (Octopus's advertised smart charging rate) |
| Times | 23:30 to 05:30 for the whole home, plus up to 6 hours of scheduled car charging in any 24 hours |
| You need | A compatible car or charger, a smart meter sending half-hourly readings and the Octopus app |
| Octopus Go | EV tariff with a fixed night window |
| Cheap rate | 9.4p/kWh off-peak |
| Times | 00:30 to 05:30 every night |
| You need | Any EV and any charger, and a SMETS2 or Secure SMETS1 smart meter |
Quick answers
- Cost of a charge = kWh added x unit rate. Cost per mile = unit rate / miles per kWh.
- At an 8p/kWh off-peak rate and 3.5 miles per kWh, a mile costs about 2.3p.
- For 10,000 miles a year that is about £229 on Intelligent Octopus Go's rate, against about £752 at the price cap's average rate.
- Octopus puts the average petrol car at 14p to 15p a mile in fuel.
The cost of charging at home comes down to two numbers: how many kilowatt-hours (kWh) you put in, and what you pay for each one. Once you have those, the sums are easy, whichever tariff you are on.
The formula
- Cost of a charge = kWh added x unit rate
- Cost per mile = unit rate / your car’s miles per kWh
- Annual cost = annual miles / miles per kWh x unit rate
Add around 10% for charging losses if you want to be cautious.
A worked example
Take a driver covering 10,000 miles a year in a car that averages 3.5 miles per kWh. That is about 2,857kWh a year.
| Where you charge | Rate used | Per mile | Per year |
|---|---|---|---|
| Intelligent Octopus Go off-peak | 8p/kWh | 2.3p | about £229 |
| Octopus Go off-peak | 9.4p/kWh | 2.7p | about £269 |
| Standard tariff at the price cap average | 26.32p/kWh | 7.5p | about £752 |
| Public rapid chargers, average | 79p/kWh | 22.6p | about £2,257 |
Rates as checked in October 2026. Your own figures depend on your region, your car and how you drive; the formula stays the same. For comparison, Octopus puts the average petrol car at 14p to 15p a mile in fuel.
Making sure all your charging is off-peak
The table assumes every kWh goes in at the cheap rate. To get close:
- On Intelligent Octopus Go, plug in as soon as you are home and avoid bump charges unless you need them.
- On Octopus Go, set the car or charger timer to 00:30 to 05:30. A 7kW charger adds about 35kWh in that time, enough for most daily driving.
The bigger picture
The car is only part of the bill. EV tariffs have a higher day rate, so what you save on charging can be eroded if much of your other use is in the day. Our guide to using the cheap hours for the whole home helps, and is an EV tariff worth it? shows how to check your whole bill.
Our methodology page lists the energy prices we use for charging costs across the site.
How we test and where our numbers come from
Tariff times, rules and rates come from Octopus Energy's own tariff pages and its public price API on the date shown. Off-peak rates quoted are national; day rates and standing charges vary by region, so check your postcode. EV Compared earns a referral reward if you switch through our Octopus links; it does not change what we write. Last checked 28 October 2026. How we work out our own figures.
Frequently asked questions
How much does a full charge cost on Intelligent Octopus Go?
Multiply the kWh you add by the off-peak rate. Adding 60kWh at 8p/kWh costs £4.80. Allow around 10% extra for charging losses.
Do I need to include the standing charge?
The standing charge is paid whether or not you own an EV, so it does not change the cost of charging. It matters when comparing tariffs, because standing charges differ between them and by region.
How many miles do I get per kWh?
Most electric cars manage 3 to 4 miles per kWh over a year, less in winter and on motorways, more in town and in summer. Your car's trip computer shows your real figure.
Sources and further reading
- octopus.energyOctopus Energy: Intelligent Octopus GoSmart charging from 7.9p/kWh; comparison assumes 8.0p off-peak; checked 28 October 2026
- api.octopus.energyOctopus price API: Octopus GoOff-peak 9.4p/kWh on 28 October 2026
- octopus.energyOctopus Energy: EV tariff FAQsAverage petrol car 14p to 15p a mile; home standard tariff about 8p; off-peak 2p to 3p a mile
- ofgem.gov.ukOfgem: energy price capElectricity unit rate cap 26.32p/kWh average, 1 October to 31 December 2026 (Direct Debit)
- zapmap.comZapmap charging price indexAverage rapid and ultra-rapid pay-as-you-go 79p/kWh, September 2026
EV Compared
The EV Compared editorial team tracks the UK electric vehicle market full time: new model launches, list prices, WLTP and real-world range, public charging tariffs and the tax rules that decide what an EV actually costs to run. Every guide is checked against manufacturer specifications and official GOV.UK figures, and updated whenever the numbers move.
Related reading
View all
EV Tariffs October 2026: Octopus, EDF and British Gas Off-Peak Rates
Intelligent Octopus Go is 8p per kWh, EDF GoElectric holds at 6.66p and British Gas EV Power sits at 9.5p. Here is what each costs, when you can charge and how to choose before winter.
How Much Does It Cost to Charge an EV at Home in the UK?
A full 60kWh charge costs around £14.80 on the standard rate or about £4.80 on an overnight EV tariff. Here is the maths, plus how to get the cheapest possible home charging cost.
How to Cut Your EV Charging Costs to Under 5p Per Mile
The tariffs, techniques and habits that get home charging below 5p per mile -- and sometimes well below