How to use it
- Pick metric or US units.
- Enter the electric car’s consumption and your price per kWh.
- Enter the petrol car’s fuel economy and fuel price.
- Enter your yearly distance and read the cost per distance and per year.
How it works
- Electric cost per distance = kWh per 100 units × price ÷ 100.
- Petrol cost per distance = L/100 km × price per litre ÷ 100, or price per gallon ÷ mpg.
- Per year = cost per distance × yearly distance; saving = petrol − electric.
Worked example
An electric car using 17 kWh/100 km at 0.15 per kWh costs 17 × 0.15 ÷ 100 = 0.0255 per km. A petrol car using 7.5 L/100 km at 1.80 per litre costs 0.135 per km. Over 15,000 km that is 382.50 against 2,025.00, a saving of 1,642.50 a year.
Tips
- Compare at your real prices. Public fast charging can cost close to petrol per distance.
- Winter raises consumption for both cars, but more for electric cars in the cold.