Should I Charge My Car?
See what you really pay per kWh, and whether charging beats gas.
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Pick your car to start.
Select your car
Don’t see your exact year? Pick the closest one. A car’s MPG and efficiency barely change within a generation, so the answer comes out about the same. The list only has plug-in hybrids. Not listed, or want exact numbers? Pick “My own car” to enter your own.
Car data: US EPA & DOE (fueleconomy.gov).
Adjust details
Your car’s usable capacity, the part you actually charge, not the full pack size a maker advertises. For a car from the list, it’s estimated from the EPA’s electric range, so it’s approximate and can vary by year.
Filled in for cars from the list. Only change these if you track your own real-world numbers. The gas and electric figures set the break-even, and battery size sets the charge time and total.
Charger
Enter each price and the time it starts (it runs until the next one). We use your device’s current time to pick the rate now and flag a cheaper window.
Set the price from the start (0 min), then add tiers that kick in after a set amount of charging time, in minutes or hours.
Charger speed, Level 2, 6.6 kW
The charger you’re plugged into, not your car. For a car from the list, the estimate already caps it at what your car can take; with “My own car”, enter whichever is lower. It sets the charge time, and the total too if the station bills by the hour or by duration. Level 1 is a North American 120 V socket; a 230 V socket gives about 2.3 kW. Anything above 22 kW counts as 22, the top of the common AC range. New charger and your next visit put it back at 6.6.
Fees (service, time, tax)
Add these only if the charger’s screen lists them.
An hourly fee for staying plugged in, on top of the energy cost. Example: free for the first 4 hr, then 5 per hour. If the charger bills by the minute, enter the per-minute price times 60. If that’s all it charges, set the energy rate to 0.
A percentage added to the whole bill. Add one row per line on the charger’s screen (e.g. state 6.25%, city 1%); we total them. Skip this if the price already includes tax, as it usually does where there’s VAT.
Charge time & cost
Set how full the battery is now and how full you want it, and when to stop if the charger bills by time. Then see how long it takes, the range you add, and the total cost.
For this charge
Common questions
Why I built this
I drive a plug-in hybrid and got tired of standing at chargers doing the same mental math every time. With this gas price and this charger rate, am I actually saving money, or just feeling good about plugging in? Half the time I could not even work out the real price per kWh, because every network prices it differently. So I built the thing I wanted. It works out what charging my PHEV actually costs and compares that against gas. You put in your car, your gas price, and what the charger costs, and it tells you charge it or use gas. It works offline too, because every charger I use is buried in a garage with no signal. It is free, there is no signup, and nothing you type leaves your device.
How do I calculate charging cost vs gas?
- Pick your car, or choose “My own car” to enter your own numbers. To keep several cars, tap “Add this car” for each one, then switch between them at the top of the car section.
- Enter today’s gas price. The buttons at the top right set your currency and units.
- Enter the charger’s price per kWh. For time-of-day or tiered pricing, pick “Time of day” or “By duration” above the rate. “Charger speed” starts at Level 2 (6.6 kW), so change it if you plug into a wall socket (Level 1) or the station lists its own kW. Add session, hourly, or tax charges under “Fees” in the same Charger section.
- Read the verdict at the top. It updates as you type. Your car, gas price, and settings are saved for next time. The battery sliders and the charger’s price, fees, and speed start fresh each visit.
- At the next charger, tap “New charger” to clear the last one’s price, fees, and speed. “Undo” puts them back.
What is “Charge time & cost” for?
This section is optional. It estimates how long a charge takes and what the whole session costs.
Set the two battery sliders and you get range added, time, and total.
The time comes from “Charger speed” in the Charger section, capped at what your car can take unless you chose “My own car”. On flat per-kWh pricing that is all the speed changes. If the station adds an hourly fee or prices energy by duration, charging slower costs more for the same kWh, so it can flip the verdict, and a “Charge for” slider appears here, under Charge to, so you can price a partial charge.
What is a break-even charging price?
The most you can pay per kWh before gas becomes cheaper. It comes from comparing cost per mile: gas is pump price ÷ MPG, electricity is charger price ÷ miles per kWh. Set the two equal and you get your break-even price.
Where do the car numbers come from?
The US EPA, via fueleconomy.gov. The electric figure is the EPA’s measured kWh per 100 miles, not a conversion from MPGe. Battery size is estimated from EPA electric range. Every value is editable.
Why can public charging cost more than gas?
The per-kWh price is often only part of the bill. Stations add session fees, hourly fees while you are plugged in, and tax. Plug-in hybrids charge slowly (over half the cars listed here take 3.6 kW at most), so hourly fees hit hard. A $2/hour fee on a 3.6 kW car adds about 56 cents per kWh by itself.
My car isn’t listed.
Choose “My own car” and enter your MPG, miles per kWh, and battery size. The list only covers 176 US plug-in hybrid models from 2012 to 2026, so any other car is missing, including ones sold only in the UK or Europe. Leave MPG empty and you still get the cost of each charge and what you really pay per kWh.