EV Charging Cost Calculator
What charging actually costs — at home, on public chargers, or off your own roof.
✏️ These numbers were filled in from a shared link — change anything to make it your own.
How charging cost is calculated
annual kWh = miles ÷ 100 × kWh per 100 miles
cost = (kWh × home share × home rate) + (kWh × public share × public rate)
The home-charging share matters more than most people expect. Going from 80% home charging to 40% can add hundreds of dollars a year, because public fast charging is often three times the price of home electricity.
Where solar changes the math
Solar electricity does not cost retail rates — it costs whatever your system works out to per kWh over its life, frequently around 5–8¢. Charging an EV off your own roof is close to the cheapest mile you can drive, and it is why solar and EV ownership reinforce each other: the car gives the panels a large, flexible daytime load to absorb.
Work out your own effective solar cost in the Solar Payback Calculator, then size for the extra load with the System Size Calculator.
Excludes charger installation, network membership fees, idle fees, and charging losses (typically 10–15% between the wall and the battery, which makes real-world costs slightly higher than shown). Rates vary by utility, time of day, and network. General information, not financial advice.
Frequently asked questions
How much does it cost to charge an EV at home?
Multiply your annual miles by your car’s efficiency in kWh per 100 miles, then by your electricity rate. A car using 30 kWh/100 miles driven 12,000 miles a year at $0.16/kWh costs about $576 a year — roughly a third of what the equivalent gas car burns.
Is public charging more expensive than home?
Substantially. DC fast charging commonly runs two to four times home electricity rates, and some networks add session or idle fees. If most of your charging is public, much of the fuel-cost advantage over gasoline disappears — set your home-charging share above to see the real blended cost.
Is charging an EV with solar free?
Not free, but close to it. Solar electricity has an effective cost — your net system price divided by lifetime production, often somewhere around 5–8¢/kWh. That is well below retail rates, which is why pairing solar with an EV is where the economics get genuinely compelling. Work out your own figure with the Solar Payback Calculator and enter it above.
What is MPGe and why use cost per mile instead?
MPGe converts electricity to a gasoline-equivalent using energy content, which is useful for efficiency comparisons but tells you nothing about cost, because electricity and gasoline are priced completely independently. Cost per mile is what actually hits your budget, which is why it is the headline figure here.