Car / Energy
EV vs Gas Cost Calculator: Energy Savings and Break-Even
Compare an electric car's energy cost with a petrol car over the same annual distance, allowing for charging losses and home/public electricity prices.
EV vs Gas Cost Calculator: Energy Savings and Break-Even: Weights electricity prices by charging energy share, adjusts battery energy for losses and compares the electricity bill with petrol cost. A positive annual saving can recover an entered purchase premium; zero or negative savings cannot. Runs 100% locally in your browser with zero server file uploads.
- Category
- Home & family tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Changing currency does not convert prices. Unit changes preserve the same physical quantities.
Enter battery-side consumption. Grid energy = battery energy ÷ (1 − charging loss). The editable 10% default follows the DOE combined-driving example; actual losses vary. If your consumption already includes charging losses, set loss to zero. DOE: Where the Energy Goes
Home and public shares refer to charging energy. Break-even is the price premium divided by annual energy savings; prices and distance stay constant. Finance, maintenance, insurance, incentives, charger installation and resale differences are excluded.
Charging-loss example
DOE's combined-driving energy diagram gives 10% charging losses and explains why actual loss varies by equipment and conditions: https://www.fueleconomy.gov/feg/atv-ev.shtml
Energy-only break-even
EV cost = distance × battery consumption ÷ (1 − loss) × weighted electricity price. Petrol cost = distance × fuel consumption × fuel price. Break-even years = price premium ÷ annual savings, only when savings are positive; no premium means nothing needs recovering.
How to use it
- Enter annual distance and battery-side EV consumption in kWh/100 km or mi/kWh.
- Set home/public electricity prices, home share, charging loss, petrol economy and fuel price.
- Read costs per distance, annual savings and years needed to recover an EV price premium.
Privacy & limitations
All energy and price calculations run in your browser.
Related tools
Frequently asked questions
Why is grid energy greater than battery energy?
Charging loses energy. With 10% loss, divide battery energy by 0.9 rather than multiplying by 1.1. Enter zero loss if your consumption figure already includes it.
What does the home share mean?
It is the percentage of charging energy bought at the home tariff. Public charging uses the remainder. Prices are per kWh and exclude session or parking fees.
Does break-even include every ownership cost?
No. It is purchase premium divided by annual energy savings at constant distance and prices. Maintenance, insurance, finance, incentives, installation and resale differences are excluded.
Free tool · runs in your browser · no account required