EV Charging Time by Charger kW
Work out how long an EV takes to charge between two battery levels for any charger power, from a home outlet to a DC fast charger.
How it works
Energy = battery × (target% − start%) · Drawn = energy ÷ efficiency · Time = drawn ÷ charger kW
Charging time is the energy you need to add divided by how fast the charger delivers it, adjusted for the energy lost as heat in the cable, charger and battery. This is a flat-rate estimate: in reality DC fast charging slows sharply above roughly 80% as the car protects the battery, so charging the last 20% can take as long as the first 60%. For that reason fast-charge stops are usually planned to 80%.
Worked example
A 60 kWh pack from 20% to 80% needs 60 × 0.60 = 36 kWh. At 90% efficiency the charger must supply 40 kWh; on a 7.4 kW Level 2 unit that is 40 ÷ 7.4 ≈ 5.4 hours.
Frequently asked questions
Why does fast charging slow down near full?
To protect the cells, the battery management system tapers the current as the pack fills. A DC charger might hold peak power to about 50–60% and then ramp down, so the last 20% is disproportionately slow — which is why road-trip stops usually target 80%.
What charger powers are common?
A standard 120V household outlet is roughly 1.4 kW, a Level 2 home or public charger is typically 7–11 kW, and DC fast chargers range from about 50 kW to 350 kW.
Why include a charging efficiency?
Not all the energy pulled from the wall reaches the battery — some is lost as heat in the onboard charger and cabling. Accounting for 85–92% efficiency makes the time estimate more realistic, especially on slower AC charging.
Related calculators
Educational estimate — real figures vary by vehicle, lender, dealer and local rules.