Evcharging Time Calculator
Free Evcharging time Calculator for fuel & energy. Enter your stats to get performance metrics and improvement targets.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Charging Time = (Battery kWh x (Target% - Current%) / 100) / (Charger kW x Efficiency)
The energy needed is the battery capacity multiplied by the difference in state of charge percentages. This is divided by the charging efficiency to account for energy losses. The result is divided by the charger power in kilowatts to get the time in hours. DC fast chargers taper above 80% SOC, requiring separate calculations for energy delivered above and below that threshold.
Worked Examples
Example 1: Overnight Home Charging
Problem:Charge a 75 kWh EV from 20% to 90% using a Level 2 home charger at 11 kW with 90% efficiency. How long will it take?
Solution:Energy needed = 75 kWh x (90% - 20%) = 75 x 0.70 = 52.5 kWh\nEnergy with losses = 52.5 / 0.90 = 58.33 kWh\nCharging time = 58.33 / 11 = 5.30 hours\nCost at $0.13/kWh = 58.33 x $0.13 = $7.58\nMiles added = 52.5 / 0.30 = 175 miles
Result:Charging time: 5h 18min | Cost: $7.58 | Miles added: ~175
Example 2: DC Fast Charging Road Trip Stop
Problem:Charge a 100 kWh EV from 10% to 80% at a 150 kW DC fast charger with 92% efficiency.
Solution:Energy needed = 100 x (80% - 10%) = 70 kWh\nEnergy with losses = 70 / 0.92 = 76.09 kWh\nCharging time = 76.09 / 150 = 0.507 hours = ~30 min\nCost at $0.35/kWh = 76.09 x $0.35 = $26.63\nMiles added = 70 / 0.30 = 233 miles
Result:Charging time: ~30 minutes | Cost: $26.63 | Miles added: ~233
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy