EV Charging Time Calculator

Estimate how long an EV charge takes from the kWh you need to add, your charger's power level, and real-world charging efficiency.

Charge & charger
kWh
Results update as you type — no submit
ResultsLIVE
Charging time
6h 10m
6.48 kW effective at the pack
Energy added40 kWh
Effective charge power6.48 kW
Charger power7.2 kW
Formula
effective = 7.2 kW × 0.9 = 6.48 kW
time = 40 kWh ÷ 6.48 kW = 6.17 h ≈ 6h 10m
DC fast charging tapers above 80% to protect the battery, so fast-charge times are a lower bound. Steady Level 2 estimates hold across most of the session.

Charging time comes down to how much energy you need divided by how fast it goes in. The energy is in kilowatt-hours: you can enter it directly, or let the tool work it out from your battery's size and the state-of-charge gap you want to close — going from `20%` to `80%` of a `60 kWh` pack is `36 kWh`. The speed is your charger's power in kilowatts, reduced by a charging efficiency that accounts for AC-to-DC conversion and thermal losses.

Charger power is what sets the pace. A Level 1 cord on a standard outlet delivers around `1.4 kW`, a Level 2 home unit about `7.2 kW`, and a Level 3 DC fast charger `50 kW` or more. Dividing the kWh you need by the effective power — charger kW times efficiency — gives the hours, which the tool shows as hours and minutes.

Real charging is not perfectly linear, especially on DC fast charging, where the rate tapers off sharply above `80%` to protect the battery. That is why most fast-charging stops target `80%`. For overnight Level 2 charging at home the estimate is close, because the car holds near its full AC rate across most of the session.

Worked example
Energy to add `40 kWh` · charger `7.2 kW` (Level 2) · efficiency `0.90`
effective power = `7.2 kW` × `0.90` = `6.48 kW`
time = `40 kWh` ÷ `6.48 kW` = `6.17 h` ≈ `6 h 10 m`
Divide the kWh you need by your charger's effective power. Adding 40 kWh on a 7.2 kW Level 2 unit at 90% efficiency takes about 6 h 10 m. The same energy on a 1.4 kW Level 1 cord would take over 30 hours, which is why a home Level 2 charger is worth it for daily driving.
SOURCESCharging levels: DOE Alternative Fuels Data Center · SAE J1772 coupler ratings
Estimates for planning only — actual times vary by battery and temperature