EV Charging Cost Calculator
Work out what it costs to charge your EV from one battery percentage to another, including charging losses, plus your cost to drive 100 miles.
Reviewed by the CalcCafe editorial team · Last updated 1 July 2026 · How we test our tools
Example
Charging a 60 kWh battery from 20% to 80% adds 60% × 60 = 36 kWh to the pack. At 90% charging efficiency the wall draws 36 ÷ 0.90 = 40 kWh. At $0.15/kWh that is a cost of $6.00 per charge. Driving at 3.5 mi/kWh, every 100 miles costs (100 ÷ 3.5) × $0.15 ≈ $4.29.
How it works
Energy from the wall = battery kWh × (to% − from%) ÷ 100 ÷ (efficiency% ÷ 100). Cost per charge = that energy × price per kWh. Cost per 100 miles = (100 ÷ miles-per-kWh) × price per kWh. Efficiency accounts for charging losses, so the wall draws slightly more than the pack actually gains.
Good to know
Charging an electric car is usually far cheaper than filling a tank, but the real number depends on more than just your electricity rate. This calculator takes your battery size, the percentage window you plan to charge across, your price per kilowatt-hour, and your charging efficiency, and returns the cost of a single charge, the energy actually pulled from the wall, and what it costs to drive 100 miles.
The efficiency field matters because not all the energy leaving your outlet ends up stored in the battery. Some is lost as heat in the cable, onboard charger, and battery management, especially on slower AC home charging in cold weather. A figure of 85–95% is typical, so entering 90% means the wall delivers about 11% more energy than the pack gains. That gap is why your utility bill can run higher than a naive "kWh added × price" estimate.
Two different efficiency numbers appear here and they measure different things. Charging efficiency is the wall-to-battery loss described above. Miles per kWh is how far the car travels on the energy in the pack, which drives the cost-per-100-miles figure. Highway speeds, climate control, and terrain all lower miles per kWh, so use a real-world average from your trip computer rather than the sticker rating for the most honest cost.
Treat the output as a planning estimate. Time-of-use rate plans, demand charges, public fast-charging premiums, and charging losses that vary by temperature can all move the true cost. For the cheapest charging, top up at home on an off-peak overnight rate and avoid repeatedly filling the last 20% of the battery, which charges more slowly and less efficiently.
Frequently asked questions
Is it cheaper to charge an EV at home or at a public charger?
Home charging is almost always cheaper. Residential electricity often runs $0.10–$0.20/kWh, while public DC fast chargers can cost two to four times more per kWh plus session fees. This tool assumes your home rate, so raise the price field to model public charging.
Why does charging efficiency make the cost higher?
Some energy is lost as heat in the cable, onboard charger and battery during charging, so the wall draws more than the pack stores. At 90% efficiency the outlet delivers about 11% more energy than the battery gains, which raises your metered cost accordingly.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Your inputs never leave your device, and it works offline once loaded.
Is this calculator free?
Yes, completely free with no sign-up and no limits.
People also ask
How much does it cost to charge an electric car?
Multiply the kWh you add by your electricity price, then divide by your charging efficiency. For a 60 kWh battery charged 20%–80% at $0.15/kWh and 90% efficiency, that is about $6.00 per charge.
How do you calculate cost per mile for an EV?
Divide your electricity price by your miles-per-kWh figure. At $0.15/kWh and 3.5 mi/kWh that is about $0.043 per mile, or roughly $4.29 per 100 miles.
Should I charge my EV to 100%?
For daily driving many manufacturers suggest charging to 80% to reduce battery wear, saving 100% charges for long trips. Charging the top 20% is also slower and slightly less efficient.
How much will my electric bill go up charging my EV?
Monthly cost = (monthly miles / miles per kWh) / charging efficiency x price per kWh. Driving 1,000 miles a month at 3.5 mi/kWh needs 1,000 / 3.5 = 286 kWh in the battery, or 286 / 0.90 = 317 kWh from the wall at 90% efficiency, which at $0.15/kWh adds about $48 to the bill. Your rate, especially any off-peak EV tariff, is the biggest variable, so check your utility bill for the actual price per kWh and enter it here.
What happens to an EV after 8 years?
Eight years is a common battery warranty length in the US and elsewhere, typically paired with a mileage cap and a guarantee of a minimum capacity such as 70%. After that the car keeps working; batteries degrade gradually rather than failing, so a well-cared-for pack usually still holds most of its original capacity and range simply shrinks somewhat. Charging cost per mile stays roughly the same because the efficiency in miles per kWh changes little, though you may charge slightly more often.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.