EV vs petrol savings calculator
See how much you'd save in a year switching to a home-charged EV on Intelligent Octopus Go. UK 2026 prices, no email required.
Your inputs
UK 2026 defaults preloaded. Adjust to your reality.
Typical UK petrol: ~45 mpg. Small hatchback: 50+. SUV/4x4: ~35.
May 2026 UK average ~£1.42/L.
Smaller EV (Renault Zoe, Nissan Leaf): ~4. Tesla Model 3: ~3.8. EV SUV: ~3.
With Intelligent Octopus Go scheduling, most home users hit 90%+.
Annual cost comparison
Petrol / diesel
£1,148
178 gallons × £1.42/L
Home EV charging
£256
2286 kWh, 80% off-peak
You save per year
£892
That's £74/month — or £4,458 over 5 years.
Excludes VED, insurance, and depreciation differences — fuel only. Public rapid charging at 60-89p/kWh would significantly reduce savings if used heavily.
Savings calculator FAQs
What's the cheapest UK EV charging tariff in 2026?
Intelligent Octopus Go is the cheapest mainstream UK EV tariff, currently around 7p per kWh off-peak (11pm-5:30am typically). EDF GoElectric and OVO Charge Anytime are competitive alternatives. Standard variable tariff is ~28-32p/kWh — 4x more expensive.
Is the £500 grant included in this savings calculation?
No — this calculator shows annual fuel savings only (charging cost vs petrol cost). The £500 grant is a one-off install subsidy, separate from ongoing running costs. Most UK households pay back the install cost within 18-30 months from fuel savings alone.
How accurate are these numbers?
Inputs are public 2026 UK figures: average petrol price ~£1.42/L, Intelligent Octopus Go off-peak ~7p/kWh, average EV consumption ~3.5 miles per kWh. Your real savings depend on driving style, tariff exactness, and whether you can shift all charging to off-peak (most home chargers can with smart scheduling).
What about public charging?
Public rapid charging in the UK runs 60-89p/kWh, dramatically reducing the savings advantage. The economics of EV ownership are strongest when 80%+ of your charging happens at home off-peak. If you have no driveway, the on-street parking grant scheme can still get you home charging.
Does the savings calculation include road tax differences?
No, only fuel. Since April 2025, EVs pay Vehicle Excise Duty (VED) like ICE cars (~£195/yr standard rate). This is small relative to the fuel savings difference (typically £1,000-£2,500/yr) but worth noting.