EV Charging Cost Calculator

Electric vehicle charging cost depends on energy used and your electricity rate. kWh needed = distance ÷ efficiency (mi/kWh or km/kWh). Total cost = kWh × price per kWh.

Real efficiency varies with speed, temperature, HVAC use, and terrain. Home rates (often off-peak) differ from DC fast-charging prices, which may include session fees or per-minute charges not modeled here.

Example: 100 miles in a car averaging 3.5 mi/kWh uses about 28.6 kWh. At $0.14/kWh, that costs roughly $4.00 — about $0.04 per mile.

Charging is not perfectly efficient, and the gap is bigger than most owners assume. AC charging at home loses roughly 10 to 15% to the onboard charger and thermal management, so a car that needs 28.6 kWh at the battery may draw closer to 32 kWh at the meter. Your utility bills the meter figure, so add about 10% to this estimate for home charging.

Cold weather is the largest single variable. Below freezing, cabin heating and battery conditioning commonly cut range 20 to 40%, which turns 3.5 mi/kWh into something nearer 2.4 and raises the cost per mile by the same proportion. Preconditioning while still plugged in shifts that energy onto the wall rather than the battery.

Public fast charging changes the arithmetic entirely. DC rates are often two to four times a residential off-peak rate, and some networks bill per minute rather than per kWh, which penalises cars that charge slowly or arrive with a warm battery. Idle fees after the session ends are also common and are not part of this estimate.

Charging past about 80% is slow and disproportionately expensive on a per-minute network, because the car tapers current to protect the cells. On a road trip, two shorter stops to 80% usually cost less time and money than one long stop to 100%.

Time-of-use tariffs reward scheduling. Many utilities price overnight energy well below the daytime rate, and EV-specific plans can go further, so setting a departure time in the car and letting it charge in the cheapest window is often the single biggest saving available — compare this result at both your peak and off-peak rate.

Compare to gas cost using our fuel cost calculator with your ICE vehicle's MPG for the same trip.