EV Charging Time Calculator
Enter battery size, charge levels and charger power to estimate charging time.
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EV Charging Time Calculator by TheCalcTools
How the EV Charging Time Calculator works
Time ≈ energy needed ÷ charging power, plus losses (about 10% for AC). On AC the car’s on-board charger caps the power, so an 11 kW car on a 22 kW point still charges at 11 kW.
DC fast chargers slow down as the battery fills; this calculator assumes 40% of the charger’s power above 80%, which is a rough average. Real curves depend on the car and temperature.
The formula
Worked example
Using the default values shown in the calculator:
| Usable battery capacity (kWh) | 75 |
|---|---|
| Starting charge | 20 % |
| Target charge | 80 % |
| Charger power | Home wall box, 7.4 kW |
| Car's maximum AC charging rate (kW) | 11 |
| Charging losses | 10 % |
- 20% to 80% of 75 kWh = 45 kWh.
- At 7.4 kW with 10% losses: 6 h 41 min.
Result:
| Charging time | 6 h 41 min |
|---|---|
| Hours (decimal) | 6.69 |
| Energy added to the battery (kWh) | 45.0 |
| Energy drawn from the grid (kWh) | 49.5 |
| Effective charging power (kW) | 7.4 |
Frequently asked questions
Why charge to 80% on a road trip?
Fast charging slows sharply near full, so stopping at around 80% and driving on is usually quicker overall.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.