Understanding the true cost of running an electric vehicle is essential for any prospective or current EV owner. The good news: EVs are significantly cheaper to "fuel" than petrol or diesel cars in almost every scenario.
The Quick Answer
Home charging: 3–6p per mile
Public charging: 8–18p per mile
Petrol equivalent: 15–22p per mile
Let's break down exactly how these figures are calculated.
Home Charging Costs
Home charging is by far the cheapest way to run an EV. The cost depends on your electricity tariff and your car's efficiency.
Standard Tariff (around 24p/kWh)
| Car Efficiency | Cost per Mile |
|---|---|
| 3.5 mi/kWh (efficient) | 6.9p |
| 3.0 mi/kWh (average) | 8.0p |
| 2.5 mi/kWh (less efficient) | 9.6p |
Off-Peak/EV Tariff (around 7p/kWh)
| Car Efficiency | Cost per Mile |
|---|---|
| 3.5 mi/kWh (efficient) | 2.0p |
| 3.0 mi/kWh (average) | 2.3p |
| 2.5 mi/kWh (less efficient) | 2.8p |
Key takeaway: With a smart EV tariff like Octopus Go or Intelligent Octopus, you can run your car for around 2–3p per mile — roughly 10% of petrol costs.
Public Charging Costs
Public charging is more expensive than home charging, but still competitive with petrol for most networks.
Slow Chargers (up to 7kW)
Fast Chargers (22–50kW)
Rapid/Ultra-Rapid Chargers (50–350kW)
Real-World Example (60kWh battery, 3 mi/kWh)
| Charging Method | Cost for 180 miles |
|---|---|
| Home (off-peak) | £4.20 |
| Home (standard) | £14.40 |
| Public (BP Pulse) | £30–40 |
| Public (Ionity PAYG) | £46 |
| Petrol (45mpg @ £1.45/L) | £26 |
Comparison With Petrol and Diesel
To compare fairly, let's look at annual fuel costs for a driver covering 10,000 miles:
Electric Vehicle
Petrol Car (45 mpg)
Diesel Car (55 mpg)
Savings: An EV driver on a smart tariff saves over £1,200 per year on fuel alone compared to a petrol car.
Factors That Affect Your Costs
1. Your Electricity Tariff
The biggest variable. Standard tariffs (24p+/kWh) versus EV tariffs (7p/kWh off-peak) make a huge difference.
Recommended tariffs:
2. Your Car's Efficiency
Efficiency varies significantly between EVs:
| Vehicle | Efficiency | Cost per Mile (7p/kWh) |
|---|---|---|
| Tesla Model 3 | 4.0 mi/kWh | 1.75p |
| Hyundai Ioniq 6 | 3.8 mi/kWh | 1.84p |
| VW ID.3 | 3.5 mi/kWh | 2.00p |
| Kia EV6 | 3.2 mi/kWh | 2.19p |
| Mercedes EQS SUV | 2.5 mi/kWh | 2.80p |
3. Driving Style and Conditions
4. How Often You Use Public Charging
The more you rely on public charging, especially rapid chargers, the higher your per-mile costs.
How to Calculate Your Own Costs
Use this simple formula:
Cost per mile = (Electricity price per kWh) ÷ (Miles per kWh)
Example:
For annual costs:
Annual cost = (Annual miles ÷ Miles per kWh) × Price per kWh
Example:
Total Cost of Ownership
Fuel is just one part of running costs. EVs also save on:
When you factor in all savings, an EV can cost £1,500–3,000 less per year to run than an equivalent petrol car.
Summary
| Charging Method | Cost per Mile |
|---|---|
| Home (off-peak EV tariff) | 2–3p |
| Home (standard tariff) | 6–10p |
| Public (slow/free) | 0–8p |
| Public (fast) | 10–18p |
| Public (rapid) | 15–25p |
| Petrol (for comparison) | 15–22p |
| Diesel (for comparison) | 12–18p |
The bottom line: If you can charge at home on an EV tariff, running an electric car costs a fraction of running a petrol or diesel vehicle. Even with public charging, EVs remain competitive — and the gap continues to widen in favour of electric.