Boneyard Tools

EV Charging Time Calculator

Estimate how long it takes to charge an electric vehicle. Enter the battery capacity, your charger power in kW, the starting and target charge levels and a charging efficiency to see the time in hours and minutes.

How to estimate EV charging time

  1. Enter the usable battery capacity in kWh.
  2. Enter the charger power in kW, from the wall box or charging station.
  3. Set the starting and target charge percentages.
  4. Adjust the efficiency if needed, then read the time in hours and minutes.

Examples

60 kWh car on a 7.4 kW charger, 20 to 80%

60 kWh, 7.4 kW, 20% to 80%, 0.9 efficiency
36 kWh needed, about 5h 24m

Frequently asked questions

Why does charging slow down near full?

Above roughly 80 percent most EVs taper the rate to protect the cells, so the last stretch takes longer. This tool assumes a steady rate, so very high targets read optimistic.

What charger power should I use?

A home outlet is about 1.4 to 2.3 kW, a wall box 7 to 22 kW, and DC fast chargers 50 kW and up. Use the lower of the charger and the car's onboard limit.

Why include an efficiency figure?

Some energy is lost as heat in the cable, charger and battery, so a little more goes in than the pack gains. The default of 0.9 reflects typical AC charging losses.

Should I use the full battery size?

Use the usable capacity, which is slightly below the total. The tool only charges the gap between your start and target percentages.

Do colder temperatures change the time?

Yes. Cold batteries charge slower, especially on fast chargers, so real times in winter can be longer than this estimate.

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