EV vs Gas Savings Calculator

What formulas does this tool use?

Annual fuel cost is distance ÷ consumption × price per unit (or distance ÷ 100 × L/100km × price per litre in Canada and Australia). Annual EV cost is distance in km ÷ 100 × kWh/100km × price per kWh. Savings are the first minus the second, and the 5-year figure is that difference times five. On 15,000 US miles at 30 MPG, $3.50 and 18 kWh/100km at $0.16, fuel is $1,750.00, charging $695.24 and the difference $1,054.76.

In what unit is the fuel-consumption box read?

It depends on the country you select: MPG (US gallons) for the US, MPG (imperial gallons) for the UK, km per litre for India, and litres per 100 km for Canada and Australia. Distance is in miles for the US and UK, and kilometres elsewhere. The starting value of 10 only makes sense as L/100km, so change it when you switch country.

What unit is the EV efficiency box?

Always kWh per 100 km, in every country. For the US and UK the tool converts your annual miles to kilometres (1 mile = 1.609344 km) before applying it. An entry of 18 therefore costs $695.24 a year over 15,000 miles at $0.16 a kWh. Entering a miles-per-kWh figure such as 3.5 here would be read as 3.5 kWh/100km and give an unrealistically low cost.

What happens if I clear the fuel price, electricity price or consumption?

A cleared box counts as 0, because the page turns an empty number box into 0, and each 0 is used literally. A fuel price of 0 makes the petrol or gas cost $0.00, an electricity price of 0 or an EV efficiency of 0 makes the electricity cost zero, and a petrol or gas consumption of 0 shows n/a for the fuel cost and the savings. The country figures (US $3.50, $0.16 and 30 MPG; UK £1.55, £0.29 and 40 MPG; India ₹105, ₹6 and 15 km/L; Canada CA$1.75, CA$0.17 and 10 L/100km; Australia A$2.10, A$0.32 and 10 L/100km; 18 kWh/100km for every country) are only the fallback used when a value is missing, which the form does not send, so type the prices you want.

Can the EV end up costing more to run?

Yes, if electricity is expensive relative to fuel. With the US inputs above, the EV is $11.91 a year cheaper at $0.40 a kWh and $31.54 a year dearer at $0.41, so the break-even sits between them. The result line says “higher with the EV” instead of showing a saving when that happens.

Is the 5-year figure a forecast?

No, it is the annual difference multiplied by five at constant prices and constant driving. It has no discounting, no price changes, no battery wear and no charging losses beyond what is built into your kWh/100km figure. A single electricity price applies to every kWh, so a mix of home and public charging should be averaged by you first.

What does the tool leave out?

The purchase price of either vehicle, maintenance, insurance, tax and registration, charging equipment, any incentives, depreciation and resale value. Only fuel and electricity are compared, so the figure is not a total cost of ownership.

What happens with a consumption of 0 or a distance of 0?

A fuel consumption of 0 cannot be converted, so the petrol/gas cost and the savings show “n/a” while the EV cost is still calculated. A distance of 0 gives zero cost on both sides. Negative numbers are treated as 0.