EV Home Charging Cost Calculator

No -- it's a reverse-engineered breakeven figure, not a market gas price. It answers "what would gasoline need to cost per gallon for a 30-MPG car to spend the same total dollars as your EV charging costs?" using a fixed 30 MPG assumption. Use it as a rough yardstick for whether your EV charging cost beats typical gas spending, not as a quote to compare against your local pump price directly. For an actual dollar comparison at a real pump price, use Monthly Gas Cost and the Gas Price input instead.

No, the 30 MPG comparison figure is fixed inside this calculator's formula and isn't one of the adjustable inputs. If your actual gas-vehicle comparison gets meaningfully better or worse mileage than 30 MPG, treat Equivalent Gas Price as directionally useful but scale it accordingly for a more personalized comparison.

Because it's a per-gallon breakeven ratio, not an absolute dollar comparison. Both your EV charging cost and the equivalent gas cost scale by the same factor when you drive more or fewer miles, so Daily Miles Driven cancels out of the equation completely -- Equivalent Gas Price reduces to (30 MPG × Electricity Rate) ÷ (EV Efficiency × Charging Efficiency). Monthly Cost, Annual Cost, and Monthly Gas Cost all DO change with mileage; Equivalent Gas Price is a fixed exchange rate between the two fuel costs, not a total.

Because Daily kWh from Grid includes charging losses that your car's trip computer doesn't see -- it only measures energy that reached the battery. This calculator divides the energy actually used by Charging Efficiency (typically around 90% for Level 2 home charging) to estimate the larger amount your utility meter registers, since some energy is always lost as heat during the AC-to-DC conversion in the charging process.

None of the three structurally dominates the others in this model -- Daily Miles Driven, EV Efficiency, and Electricity Rate each enter the cost formula as a direct multiplier or divisor, so nudging any single one of them by some fraction shifts Monthly Cost by roughly that same fraction. In practice, EV Efficiency is usually the hardest one to change (it's mostly fixed by your vehicle), while driving less or finding a lower off-peak electricity rate are the two levers you can actually act on.