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EV Charging Cost & Time Calculator

Calculate how long it takes to charge your EV and how much a full charge costs.

Result

Charging Time
6.1 hours
Charging Cost
$7.2
Energy Added
45 kWh

About the EV Charging Calculator

The EV Charging Cost & Time Calculator estimates how many hours it takes to charge an electric vehicle between two charge levels and what that charge costs at your electricity rate. It's built around your specific battery size and charger power, so the estimate reflects your actual setup rather than a generic charging time you might see quoted for a different vehicle or charger.

How It Works

You provide your battery's total capacity in kWh, your current and target charge percentages, the power rating of the charger in kW, and your electricity rate. The calculator converts the charge-level difference into kWh needed, divides that by charger power to get charging time in hours, and multiplies the kWh needed by your rate to get the cost.

Energy needed in kWh = battery capacity x (target charge percent - current charge percent). Charging time in hours = energy needed / charger power in kW. Charging cost = energy needed x electricity rate per kWh.

Examples

Overnight Level 2 top-up

A 75 kWh battery going from 20 percent to 80 percent needs 45 kWh. On a 7.4 kW Level 2 home charger that takes about 6.1 hours, and at $0.16 a kWh the session costs about $7.20.

DC fast charging stop

A 60 kWh battery going from 10 percent to 90 percent needs 48 kWh. On a 150 kW DC fast charger that's about 0.32 hours, or roughly 19 minutes, and at $0.14 a kWh the charge costs about $6.72, though real fast-charging sessions run longer than this linear estimate once the battery tapers past 80 percent.

Advantages

  • Converts charger specs and battery percentages into two numbers most drivers actually plan around: how long to wait and what it costs.
  • Works for any combination of home Level 1 or Level 2 charging or public DC fast charging, since charger power is a direct input rather than a fixed category.
  • Makes it easy to compare the cost of topping up at home versus at a public charger by rerunning the calculation with a different rate.

Common Mistakes

  • Assuming charging time scales linearly all the way to 100 percent, when real-world tapering above 80 percent makes the last portion of a charge slower than this straight-line estimate.
  • Using a charger's maximum rated power instead of the actual power it delivers to that specific vehicle, which is often lower due to onboard charger limits or shared station capacity.
  • Forgetting that public charging rates, often billed per kWh or per minute, can differ substantially from a home electricity rate, making the cost comparison inaccurate if the wrong rate is used.

Edge Cases to Watch For

  • If the target charge percentage is set equal to or below the current charge percentage, the calculator returns an error instead of a negative or zero charging time, since that combination isn't a valid charging session.
  • The math assumes a constant charging rate for the whole session; real batteries taper their charging speed above roughly 80 percent to protect battery health, so charging from 80 to 100 percent typically takes noticeably longer per kWh than this linear estimate suggests.
  • A charger power of zero is guarded against directly, returning zero hours rather than a division error.

Common Use Cases

  • EV owners planning a road trip who want a rough estimate of charging stop duration at a given charger power.
  • Someone deciding between a Level 1, Level 2, or DC fast home or public charging setup based on time tradeoffs.
  • Drivers estimating their monthly charging costs from a known daily or weekly charging pattern.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Why do charging speeds slow down near 80-100%?

This calculator assumes a constant charge rate for simplicity, but real EV batteries taper their charging speed above roughly 80% to protect battery health - fast charging from 20-80% is typically much quicker per kWh than the final 80-100%, which is why many drivers habitually charge to 80% for daily use.

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Conclusion

This calculator turns battery capacity, charge levels, and charger power into a straightforward time-and-cost estimate for a single charging session. Because it assumes a constant charge rate, treat the time figure as a lower bound for sessions that charge past about 80 percent.