EV Charging Cost Calculator
Work out what one charge actually costs — at home, on a public Level 2 unit, or at a DC fast charger — then see the cost per mile, the monthly and yearly totals, and how it stacks up against filling a gas tank.
Your car and charging session
Electricity rates
How to use this calculator
1. Describe the charge, not the battery
Almost nobody plugs in at 0% and unplugs at 100%. Enter the capacity of your pack, then the start and finish state of charge you actually use — 20% to 80% is the everyday habit most manufacturers recommend. The energy you buy is the slice between those two numbers, not the whole battery.
2. Leave room for charging losses
The efficiency box is the gap between what the meter counts and what reaches the battery. Set it near 90% for a home Level 2 wallbox, lower if you charge from a household outlet or in freezing weather when the car spends energy warming the pack. It is the one input people forget, and it quietly moves every result by about a tenth.
3. Put in three real rates
Read your home rate off an electricity bill rather than guessing — off-peak overnight windows are often half the headline price. Then check what your nearby public Level 2 and DC fast networks charge per kWh. Networks that bill by the minute instead of by the kWh can be approximated by dividing a typical session total by the kWh you added.
4. Drag the mileage slider
Monthly miles drive every yearly figure on the page. Slide it and watch the home-versus-fast-charging gap open up; a driver covering 500 miles a month and one covering 2,000 face very different math on whether a home charger installation pays for itself.
EV charging cost FAQs
How do you calculate the cost of one charging session?
First work out the energy that has to land in the pack: battery capacity × (finish % − start %). Then divide by the charging efficiency, because some of what the meter counts is lost as heat in the cable, the charger and the battery itself. Multiply that drawn figure by the price per kWh. A 75 kWh pack taken from 20% to 80% needs 45 kWh in the battery, draws about 50 kWh at 90% efficiency, and costs $7.50 at 15¢ per kWh.
Why does charging efficiency matter?
Your utility bills you for the energy that passes through the meter, not the energy that ends up in the battery. Level 1 and Level 2 AC charging typically lands between 85% and 92%, while DC fast charging is a little better at the cable but worse in cold weather because the car spends energy heating the pack. Ignoring the loss understates your real cost by roughly 10%.
Why is DC fast charging so much more expensive than home charging?
A fast charging site pays for high-power hardware, grid connection upgrades, maintenance and utility demand charges, all recovered over relatively few kWh. That is why public DC pricing commonly runs three to four times a residential rate. Fast charging is a road-trip tool rather than a daily habit, and the comparison table on this page puts a yearly number on the difference.
How do I convert between mi/kWh and kWh/100 mi?
They are reciprocals scaled by 100 — divide 100 by one to get the other. So 3.5 mi/kWh is 100 ÷ 3.5, or about 28.6 kWh per 100 miles. The unit selector next to the efficiency box does the conversion for you and rewrites the number when you switch, so you can enter whichever figure your car's display shows.
Is charging an EV actually cheaper than buying gasoline?
At typical residential electricity prices, yes, usually by a wide margin. The comparison flips only when you rely on premium DC fast charging for most of your miles, or when local electricity is unusually expensive relative to fuel. Enter your own mpg and pump price and this page prints the cost per mile for both, so you can see exactly where the crossover sits for your rates.
Should I charge to 100% every time?
Most manufacturers suggest keeping a lithium-ion pack roughly between 20% and 80% for daily driving and saving full charges for long trips, which is why those are the defaults here. Cost scales with the kWh you add, so a smaller daily top-up simply costs proportionally less — charging little and often is neither cheaper nor more expensive per mile, it is just gentler on the battery.