EV vs Gas Calculator

About this calculator

Electric cars usually cost more to buy but less to run, so the real question is whether the cheaper energy and upkeep make up for the higher sticker price — and how long that takes. This calculator compares the yearly running cost of a gasoline car (fuel plus maintenance) with an electric one (electricity plus maintenance), tells you which is cheaper to operate, and works out the break-even point if the EV costs more upfront. It is deliberately a cost-and-time tool: emissions and CO₂ are left out because we do not ship unsourced emission factors.

How to read your results

The headline is the yearly difference in running cost: when the EV is cheaper the eyebrow reads "EV saves per year"; when cheap fuel or pricey electricity tips it the other way it reads "Gas is cheaper by". The stats show each car's full yearly cost and the break-even time — how many years of running savings it takes to repay the EV's higher purchase price. Break-even shows a dash whenever there is nothing to repay (the EV costs no more upfront) or nothing to repay it with (the gas car is cheaper to run). The optional chart traces the cumulative EV-minus-gas cost difference: it starts at the upfront premium and crosses zero at the break-even year.

Worked example

US units: 12,000 miles a year, a 30 MPG gas car with gas at $3.50 a gallon, a 3.5 mi/kWh EV with electricity at $0.15/kWh, $600 a year gas maintenance vs $300 for the EV, and an EV that costs $8,000 more to buy.

Gas fuel is 12,000 ÷ 30 × $3.50 = $1,400, so $2,000 a year with maintenance. EV energy is 12,000 ÷ 3.5 × $0.15 = $514.29, so $814.29 a year with maintenance. The EV saves about $1,185.71 a year to run, and its $8,000 premium pays back in roughly 6.7 years.

Frequently asked questions

Why does this calculator ignore emissions and CO₂?

Emissions depend on local electricity-grid mix, fuel blend, and well-to-wheel assumptions that vary widely and need sourced, region-specific factors. Rather than ship numbers we cannot stand behind, this tool focuses on what you can measure directly from your own bills: running cost and how long an EV takes to pay back its higher purchase price. For carbon figures, use a dedicated source that publishes its grid and fuel emission factors.

What does "break-even" mean here, and why is it sometimes a dash?

Break-even is the number of years of running savings it takes to repay the EV's higher upfront price. It only exists when both things are true: the EV costs more to buy (a positive price premium) and is cheaper to run (positive annual savings). If the EV costs no more upfront, there is nothing to repay; if the gas car is cheaper to run, there are no savings to repay it with. In either case the calculator shows a dash instead of a misleading number.

When can a gas car actually be cheaper to run?

When fuel is cheap and electricity is expensive, or the gas car is very fuel-efficient while the EV is not. For example, an efficient 50 MPG hybrid with $2 gas can beat a heavy EV charged at $0.40/kWh. The calculator flips to "Gas is cheaper by" in those cases. Charging mostly at home off-peak versus relying on public fast-charging can swing the EV's side of the comparison dramatically.

Why do I enter values in the displayed unit instead of converting?

Switching between US and metric just changes which formula and labels apply — it does not convert your existing numbers. So in US mode you enter miles, MPG, and price per gallon; in metric mode you enter kilometres, litres per 100 km, and price per litre. Enter the figures as they appear on your own dashboard and bills, and the calculator uses the matching formula directly with no hidden conversion.

How it's calculated

In US units, gas fuel cost per year = annual miles ÷ MPG × gas price per gallon, and EV energy cost per year = annual miles ÷ (miles per kWh) × electricity price per kWh. In metric units, gas fuel cost per year = annual km ÷ 100 × (L/100km) × gas price per litre, and EV energy cost per year = annual km ÷ 100 × (kWh/100km) × electricity price per kWh. Each car's yearly total adds its annual maintenance. Annual savings = gas yearly cost − EV yearly cost (positive means the EV is cheaper to run). Break-even years = the EV price premium ÷ annual savings, shown only when the EV both costs more upfront and is cheaper to run; otherwise there is no break-even. Emissions and CO₂ are intentionally excluded — this compares cost and payback time only, and is an estimate rather than financial advice.