EV Charging Time Calculator
Estimate how long it takes to charge an electric car from one battery percentage to another using battery size, charger power, and charging efficiency.
Last reviewed: 2026-06-14
Estimated result
Energy needed Enter values
Wall energy Enter values
Estimated time Enter values
Charging note Enter values
Charging prices and charging speeds vary. Use this as a planning estimate.
Formula
energy needed (kWh) = battery capacity (kWh) x (target % - current %) / 100charging hours = energy needed (kWh) / (charger power (kW) x efficiency)Example
A 75 kWh EV charging from 20% to 80% needs about 45 kWh in the battery. At 11 kW and 90% efficiency, the estimate is about 4 hours and 33 minutes.
Assumptions and limits
- Real charging can slow down above about 80% state of charge.
- Cold or hot battery temperatures can change charging speed.
- Vehicle onboard charger limits may reduce AC charging power.
FAQ
Why is this an estimate?
The formula uses battery size, charger power, and efficiency. Real charging also depends on temperature, battery management, charger sharing, and the vehicle charging curve.
Why does the calculator warn above 80%?
Many EVs reduce charging speed near a high state of charge to protect the battery, so a simple average-power formula can be optimistic.