EV Charging Cost Calculator
See what a full charge, a single mile, and a month of driving really cost — from your battery size, efficiency, and electricity rate.
📖 How it works & FAQWhat it really costs to charge an EV
Charging an electric car is usually far cheaper than filling a gas tank, but the numbers on your utility bill make it hard to see by how much. This calculator turns three figures you already have — your battery's capacity in kWh, your car's efficiency in miles per kWh, and your electricity rate — into the three costs that actually matter: a full charge, a single mile, and a month of driving. The math is simple and transparent: full charge = battery kWh × rate, cost per mile = rate ÷ efficiency, and monthly cost is your miles driven times that per-mile figure.
Finding your numbers
Battery capacity is in your car's specs — most EVs land between 40 and 100 kWh. Efficiency shows on your dashboard or app as mi/kWh; typical values run 2.5 (large SUVs and trucks) to 4+ (efficient sedans). Your home electricity rate is on your utility bill — the US average is roughly $0.17 per kWh, though overnight EV plans can be far lower and DC fast chargers often run $0.30–$0.50. Change the rate to compare home charging against a public network in seconds.
How to use it
- Enter your battery size in kWh from your car's specs.
- Enter your real-world efficiency in miles per kWh from the trip screen.
- Enter the electricity rate you actually pay per kWh.
- Enter roughly how many miles you drive per month.
- Read the cost per full charge, per mile, and per month — results update as you type.
These figures are estimates for planning and comparison, not professional or financial advice.
FAQ
- Does this account for charging losses?
- No — the math assumes every kWh you pay for reaches the battery. Real sessions lose about 5–12% to heat and conversion, so nudge your rate up slightly (or your efficiency down) for a fuller picture.
- My car shows Wh/mi or kWh/100 mi — how do I convert?
- Divide 1000 by your Wh/mi figure, or divide 100 by your kWh/100 mi figure. For example, 285 Wh/mi and 28.5 kWh/100 mi both equal 3.5 mi/kWh.
- How do I compare against a gas car?
- A gas car's cost per mile is fuel price divided by MPG. At $3.60/gal and 30 MPG that is 12¢/mi — versus 4.9¢/mi for an EV at 3.5 mi/kWh and $0.17/kWh.
- Is anything I type sent to a server?
- No. Everything runs entirely in your browser — nothing is uploaded, tracked, or stored.