EV vs Petrol Cost Comparison Calculator
Compare the estimated running cost of an electric vehicle and a petrol car using energy consumption, fuel prices and annual driving distance.
Enter Vehicle & Cost Details
Enter the figures from the vehicles or tariffs you want to compare. The calculator uses the supplied values and does not retrieve vehicle or energy prices from an external API.
EV vs Petrol Running Cost
| Comparison | EV | Petrol |
|---|---|---|
| Energy/Fuel Consumption | — | — |
| Cost per 100 km | — | — |
| Annual Running Cost | — | — |
Step-by-Step Calculation
What Is an EV vs Petrol Cost Comparison?
This calculator compares the energy or fuel cost required to operate an electric vehicle (EV) and a petrol car. It converts the supplied consumption and energy prices into a common cost-per-distance measure and then estimates annual running cost from the annual distance entered.
The result is a running-cost comparison, not a complete ownership-cost model. Insurance, servicing, tyres, depreciation, financing, taxes and other ownership expenses are not automatically included.
How the EV Running Cost Is Calculated
EV consumption is normally expressed in kilowatt-hours per 100 kilometres. The calculator multiplies that consumption by the electricity price to estimate the electricity cost for 100 km.
Annual EV running cost is then calculated from the annual distance:
How the Petrol Running Cost Is Calculated
Petrol consumption is entered in litres per 100 kilometres. The calculator multiplies this value by the petrol price per litre.
Worked Example
Suppose an EV consumes 16 kWh/100 km and electricity costs 0.20 per kWh. A petrol car consumes 7 L/100 km and petrol costs 1.80 per litre. With 15,000 km of annual driving:
- EV cost per 100 km = 16 × 0.20 = 3.20
- Petrol cost per 100 km = 7 × 1.80 = 12.60
- Annual EV running cost = 3.20 × 15,000 ÷ 100 = 480
- Annual petrol running cost = 12.60 × 15,000 ÷ 100 = 1,890
The difference in this example is 1,410 per year before considering other ownership costs.
What Can Change the Comparison?
Electricity Price and Charging Conditions
Home electricity tariffs, public charging prices, time-of-use rates and charging losses can change the effective cost of operating an EV.
Petrol Price
Petrol prices can change over time and may vary by location and station. Use a representative price for the period you want to analyse.
Real-World Consumption
Temperature, traffic, driving style, speed, payload, air-conditioning and road conditions can make actual consumption different from a published specification.
Annual Distance
Higher annual mileage generally increases the absolute difference between two running costs because both costs are multiplied by distance.
Purchase Price and Break-Even Considerations
An EV can have a different purchase price from a comparable petrol vehicle. A lower running cost does not by itself determine whether the purchase is financially preferable. A broader analysis can compare the purchase-price difference with annual running-cost savings.
If purchase prices are supplied, this calculator can show the difference in upfront price and estimate a simple running-cost break-even period. This is only a simplified calculation and does not include financing, depreciation, maintenance, taxes or resale value.
What This Calculator Includes and Excludes
Included
- EV electricity consumption
- Petrol fuel consumption
- Electricity and petrol prices
- Annual driving distance
- Cost per 100 km
- Estimated annual energy/fuel cost
- Optional purchase-price comparison
Not Automatically Included
- Charging losses or charger efficiency
- Public charging fees beyond the electricity price entered
- Home charging equipment
- Insurance
- Maintenance and servicing
- Tyres and repairs
- Vehicle depreciation and resale value
- Loan interest and financing costs
- Taxes, registration and incentives
How to Make a Fair EV vs Petrol Comparison
Use comparable vehicles and consistent conditions. Ideally, use the same driving distance and representative local energy prices. If possible, use real-world consumption data from the same type of driving rather than mixing laboratory figures for one vehicle with observed figures for another.
Accuracy, Assumptions and Limitations
The arithmetic is deterministic: the calculator applies the supplied consumption, price and distance values directly. Results are estimates because the quality of the output depends on the input data.
- Consumption values should use compatible units.
- Prices should use the same currency.
- Annual distance should represent expected driving.
- Published efficiency figures may differ from real-world use.
- The calculator does not forecast future energy or fuel prices.
How to Use the Calculator
- Enter EV energy consumption in kWh/100 km.
- Enter electricity price per kWh.
- Enter petrol consumption in L/100 km.
- Enter petrol price per litre.
- Enter expected annual driving distance.
- Enter a currency symbol.
- Optionally enter purchase prices.
- Click Calculate Comparison.
Frequently Asked Questions
Is an EV always cheaper to run than a petrol car?
Not necessarily. The result depends on electricity price, petrol price, vehicle efficiency, charging conditions and driving conditions.
What does kWh/100 km mean?
It describes how many kilowatt-hours of electricity an EV uses to travel 100 kilometres.
What does L/100 km mean?
It describes how many litres of petrol a vehicle uses to travel 100 kilometres.
Can I compare vehicles from different countries?
Yes, if the consumption units and energy prices are entered consistently.
Does the calculator include charging losses?
No. Entering a real-world charging-inclusive consumption figure can provide a more representative estimate.
Does it include maintenance?
No. The main result compares energy and fuel running costs.
Can I calculate five-year savings?
The annual difference can be multiplied by five for a simple five-year running-cost estimate, assuming the inputs remain unchanged.
Does it account for changing petrol prices?
No. It uses the petrol price entered for the calculation.
Can I use home and public charging prices?
You can calculate separate scenarios by entering the effective electricity price for each charging situation.
Is this a total cost of ownership calculator?
No. It is primarily an energy and fuel running-cost comparison with optional purchase-price and simple break-even information.
Calculation Method and Data Sources
The calculator uses standard unit relationships and arithmetic based entirely on the values entered by the user. Vehicle consumption figures should be taken from reliable manufacturer specifications, independent tests or the user’s own records. Energy and fuel prices should be taken from the relevant local tariff, charging provider or fuel station at the time of analysis.
Related Calculators
Use the main Car Comparison Calculator to compare other vehicle specifications.