EV charging time: kWh, kW and charging losses
Estimate how long an electric vehicle takes to charge from one battery percentage to another, with a worked home-charging example.
Find the energy the battery needs
Battery energy added = usable capacity × (target charge − starting charge). A 60 kWh usable battery going from 20% to 80% needs 60 × 0.60 = 36 kWh in the battery. Battery capacity is energy (kWh); charger rating is power (kW). Keep these units separate.
Allow for power and efficiency
At a steady 7.2 kW delivered from the wall with 90% overall charging efficiency, time ≈ 36 ÷ (7.2 × 0.90) = 5.56 hours. That is a simplified estimate, not a promised finish time. A vehicle may limit charging power and DC fast charging often slows as the battery fills. Try your vehicle and charger in the EV charge time calculator.
Plan the energy cost too
Wall energy in this example is 36 ÷ 0.90 = 40 kWh. Multiply by the applicable price per kWh, adding any session or time fees separately. Use the charging cost calculator and read the EV charging cost guide. The Alternative Fuels Data Center explains why charging time depends on vehicle and equipment.