Cost Per kWh vs Cost Per Gallon Calculator
Instantly compare the fuel costs of driving an electric vehicle versus a gas-powered car based on your monthly mileage and local energy rates.
Compare Your Fuel Costs
Enter your typical monthly driving distance, vehicle efficiency, and local fuel/energy rates. The calculator instantly projects your monthly and annual fuel expenses for both vehicle types.
Fuel Expense Estimator
See how electric charging and traditional petrol/diesel costs compare for your driving habits.
Understanding the Metrics
Key factors that influence your true vehicle running costs
Miles per kWh
This is the electric equivalent of MPG. Most modern EVs achieve between 3.0 and 4.5 miles per kWh, depending on driving style, weather, and vehicle size.
Home vs. Public Charging
Home charging is almost always the cheapest option. Public rapid chargers can cost up to £0.70+ per kWh, which narrows the savings gap with petrol, though it usually remains cheaper per mile.
Fuel Price Volatility
Petrol and diesel prices are tied to global oil markets and can fluctuate wildly. Electricity prices are generally more stable, especially when locked into a fixed-rate home energy tariff.
Maintenance Savings
While this calculator focuses on fuel, remember that EVs also save money on maintenance. They have fewer moving parts, no oil changes, and regenerative braking extends brake pad life significantly.
Electric vs Gas Overview
Generalised comparisons to help you understand the broader differences between electric and internal combustion engine vehicles.
| Feature | Gas Vehicle | Electric Vehicle (EV) |
|---|---|---|
| Fuel Cost per Mile | Higher (Subject to global oil market volatility) | Lower (Especially with home off-peak charging) |
| Maintenance | Higher (Oil changes, filters, exhaust, more moving parts) | Lower (Fewer moving parts, regenerative braking saves brakes) |
| Environmental Impact | High (Direct tailpipe CO₂ and pollutant emissions) | Low (Zero tailpipe emissions; overall footprint depends on grid) |
| Refuelling Time | Fast (3 to 5 minutes at a petrol station) | Slower (30 mins to several hours, though mostly done overnight at home) |
| Best For | Frequent long road trips, areas with poor charging infrastructure | Daily commuting, home charging owners, eco-conscious drivers |
Fuel Cost Calculator FAQ
Answers to the most frequently asked questions about electric vehicle charging costs and gas savings.
In the vast majority of cases, yes. Charging an electric vehicle at home is significantly cheaper per mile than purchasing petrol or diesel. While public rapid charging can be more expensive, it still generally undercuts the cost per mile of a traditional gas vehicle.
Divide your electricity cost per kWh by your vehicle’s efficiency in miles per kWh. For example, if electricity costs £0.28 per kWh and your EV gets 3.5 miles per kWh, your cost per mile is £0.08 (8 pence).
The average UK household electricity rate fluctuates but typically ranges between £0.24 and £0.30 per kWh. Many EV owners save even more by utilising off-peak overnight tariffs, which can drop the cost to around £0.10 to £0.15 per kWh.
Yes. EVs have far fewer moving parts than internal combustion engine vehicles. They do not require oil changes, spark plug replacements, or exhaust system repairs. Additionally, regenerative braking significantly extends the life of brake pads.
Yes, cold weather can reduce an EV’s efficiency by 10% to 30% because the battery uses extra energy to heat the cabin and maintain optimal battery temperature. This means you will use more kWh per mile, slightly increasing your cost per mile during winter months.