EV Charging Cost Calculator

How it works

Energy used = miles ÷ efficiency, then divided by (1 − charging losses) to account for power lost while charging. Cost = energy × your electricity rate. We scale the daily figure to 30.4 days per month and 365 days per year.

Worked example, step by step

Take the default numbers: 30 miles of daily driving, an EV rated at 3.5 miles per kWh, a home electricity rate of $0.17/kWh, and 10% charging losses.

Energy needed from the wall = (30 miles ÷ 3.5 mi/kWh) ÷ (1 − 0.10) = 8.57 kWh ÷ 0.9 = 9.52 kWh per day.

Cost per day = 9.52 kWh × $0.17 = $1.62.

Cost per mile = $1.62 ÷ 30 miles = about 5.4 cents per mile.

Cost per month = $1.62 × 30.4 days = $49.

Cost per year = $1.62 × 365 = $591.

For comparison, a gas car averaging 30 mpg at $3.50/gallon covering the same 30 miles/day costs about $3.50/day, or roughly $106/month — more than double the EV figure above.

Why your real cost per mile will differ

Cold weather is the single biggest real-world factor this simple model does not capture directly — EV efficiency commonly drops 20-40% in freezing temperatures due to battery heating/cooling and cabin heating draw, meaning winter costs per mile can run noticeably higher than the number above. Enter a lower efficiency (e.g. 2.5-3.0 mi/kWh instead of 3.5) to model a cold-climate winter.

Highway driving at sustained high speed is also less efficient than the mixed-driving figures manufacturers often quote, due to aerodynamic drag increasing sharply with speed — a long highway trip can use noticeably more energy per mile than city/suburban driving.

Time-of-use electricity rates can cut this cost substantially if you can schedule charging for off-peak hours — many utilities offer overnight rates 30-50% below peak daytime pricing, which for a car charged mostly overnight (the most common pattern) can meaningfully lower the effective rate compared to your blended average bill rate.

Charging losses vary by equipment: a modern Level 2 home charger typically loses less energy to heat than an older Level 1 (standard outlet) setup, so the 10% default is a reasonable middle estimate rather than a fixed constant.

Frequently asked questions