EV vs Gas Cost Calculator
Compare electric and petrol driving costs per mile or km using your local fuel and electricity prices, with yearly savings and payback.
In short
Compare electric and petrol driving costs per mile or km using your local fuel and electricity prices, with yearly savings and payback.
Formula: Fuel per mile = fuel price ÷ mpg (or per km = L/100 km ÷ 100 × price per litre). EV per mile or km = kWh/100 ÷ 100 × price per kWh. Yearly saving = (fuel per unit − EV per unit) × distance per day × days. Payback = extra EV price ÷ yearly saving.
What this calculator does
Compare electric and petrol driving costs per mile or km using your local fuel and electricity prices, with yearly savings and payback.
You enter units, distance driven per day, driving days per year and fuel car efficiency and a few other details, and the ev vs gas cost calculator shows the answer along with the working, so you can check it or try other numbers.
The page shows the formula, a numeric worked example, and the assumptions that affect this energy calculation.
Inputs and what they mean
- Units
- — choice value.
- Distance driven per day
- — number value.
- Driving days per year
- — number value.
- Fuel car efficiency
- — mpg in miles mode, L/100 km in kilometre mode.
- Fuel price
- — Per gallon or per litre.
- EV energy use
- — kWh per 100 miles or per 100 km.
- Electricity price per kWh
- — number value.
- Extra purchase price of the EV (optional)
- — number value.
- Currency (symbol only, never converted)
- — choice value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Enter the price you actually pay to charge, including any public charging mix and charging losses if you know them.
Fuel per mile = fuel price ÷ mpg (or per km = L/100 km ÷ 100 × price per litre). EV per mile or km = kWh/100 ÷ 100 × price per kWh. Yearly saving = (fuel per unit − EV per unit) × distance per day × days. Payback = extra EV price ÷ yearly saving.
Inputs used: Units, Distance driven per day, Driving days per year, Fuel car efficiency, Fuel price, EV energy use, Electricity price per kWh, Extra purchase price of the EV (optional), and other shown inputs.
Worked example
40 miles a day, 250 days, 30 mpg at 3.50 vs 30 kWh/100 mi at 0.15
- Gas = 3.50 ÷ 30 = 0.11667 per mile.
- EV = 0.30 × 0.15 = 0.045 per mile.
- Saving = 0.07167 × 10,000 = 716.67.
- Payback = 5,000 ÷ 716.67 ≈ 6.98 years.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Energy costs only; no maintenance, insurance, tax, incentives or resale value.
- Assumes constant prices and efficiency all year.
- Charging losses are only included if your figures include them.
- An estimate built only from the figures you enter. It is not financial, tax, legal or employment advice, and real costs, taxes and returns vary.
- The result depends on the values you enter for this ev vs gas cost calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: FuelEconomy.gov
Last reviewed:
Common questions
Why don't you fill in fuel and electricity prices?
Prices vary widely by place and time, so you enter your own local prices.
Does it include maintenance or insurance?
No. It compares energy cost only.
Where do I find my EV's kWh/100?
From the manufacturer, the official efficiency label for your country, or your car's trip computer.
How do I use the EV vs Gas Cost Calculator?
Enter the required values for Units, Distance driven per day, Driving days per year, Fuel car efficiency, Fuel price, and the other fields shown. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the EV vs Gas Cost Calculator use?
Fuel per mile = fuel price ÷ mpg (or per km = L/100 km ÷ 100 × price per litre). EV per mile or km = kWh/100 ÷ 100 × price per kWh. Yearly saving = (fuel per unit − EV per unit) × distance per day × days. Payback = extra EV price ÷ yearly saving. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the EV vs Gas Cost Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Sources
Method based on FuelEconomy.gov.
Cite this page
Free Calculator. (2026, November 3). EV vs Gas Cost Calculator. https://freecalculator.tech/tools/ev-vs-gas-cost-calculator
"EV vs Gas Cost Calculator." Free Calculator, 3 Nov. 2026, https://freecalculator.tech/tools/ev-vs-gas-cost-calculator.
EV vs Gas Cost Calculator — Free Calculator, https://freecalculator.tech/tools/ev-vs-gas-cost-calculator
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