EV Charging Time & Cost Calculator
Charging time (hours) ≈ (battery kWh × % to add) ÷ (charger kW × efficiency). Charging a 75 kWh battery from 20% to 80% on an 11.5 kW Level 2 charger takes about 4.3 hours at roughly 90% efficiency.
That adds about 158 miles of range. Driving those miles on gas at 30 MPG and $3.40/gal would cost $17.85 — charging saves you about $9.85.
How to use the ev charging calculator
Enter your own numbers in the fields above and the result updates instantly — there is no submit step, no account, and no data leaves your browser. Everything is computed client-side from the values you type, so you can try several scenarios back to back and compare the outcomes without reloading the page.
For the most realistic result, use figures that reflect how you actually drive rather than best-case numbers. Fuel prices vary by state and by season, annual mileage is usually higher than people estimate, and EPA combined MPG is a laboratory rating that most drivers fall roughly 10-15% short of in mixed real-world use — more in cold weather, heavy traffic, or at sustained highway speeds. Running the calculation twice, once with optimistic inputs and once with conservative ones, gives you a realistic range instead of a single misleading number.
Treat the output as a planning estimate, not a quote. It does not include insurance, registration, financing interest, depreciation, or unscheduled repairs, all of which can move total ownership cost more than fuel does over a five-year window.
Frequently asked questions
How does the ev charging calculator work?
Charging time (hours) ≈ (battery kWh × % to add) ÷ (charger kW × efficiency). Charging a 75 kWh battery from 20% to 80% on an 11.5 kW Level 2 charger takes about 4.3 hours at roughly 90% efficiency.
Why isn't charging 100% efficient?
Some energy is lost as heat in the battery, charger and cables during AC-to-DC conversion. Level 2 home charging is typically about 85-90% efficient; DC fast charging is usually a bit higher.
Is DC fast charging always the best choice?
It's the fastest, but charging speed tapers sharply above about 80% state of charge to protect the battery, and frequent fast charging can accelerate long-term battery wear compared with Level 2 charging.
Is it free?
Yes. The calculator runs entirely in your browser, needs no sign-up, and nothing you enter is stored or sent anywhere.
Where can I find my vehicle's specs?
Look it up on its AutoSpecData model page — every figure comes from official manufacturer and EPA data, broken out by year, engine and drivetrain.
Don't know your MPG?
Every vehicle on AutoSpecData lists its official EPA city, highway and combined ratings year by year. Search your vehicle or start from the fuel economy rankings.