EV charging time calculator
Enter the battery capacity, the charge level you start and finish at, and the power of the charger and your car. You get the charging time in hours and minutes, the energy added, and what it costs from the grid.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Enter the battery capacity in kWh and the start and target charge levels.
- Enter the power of the charger and the highest power your car accepts.
- Adjust the efficiency and the electricity price if you know them.
- Read the time, the energy added and the cost.
How it works
- Energy added = capacity × (target − current) ÷ 100.
- Power used = the lower of charger power and car limit.
- Time = energy added ÷ (power used × efficiency).
- From the grid = energy added ÷ efficiency; cost = grid energy × price.
Worked example
A 60 kWh battery charged from 20% to 80% adds 36 kWh. On an 11 kW home charger at 90% efficiency the charge runs at 9.9 kW, so it takes 36 ÷ 9.9 = 3.64 h, which is 3 h 38 min. The grid supplies 40 kWh, costing 6.00 at 0.15 per kWh.
Tips
- Stop at 80% on fast chargers. The speed drops sharply above that for most cars.
- Plan with a margin. Cold weather slows charging.
- Treat it as an estimate. The tool does not model a charging curve.
Frequently asked questions
How is the charging time calculated?
Energy to add = capacity × (target − current) ÷ 100. Time = that energy ÷ (charging power × efficiency). For a 60 kWh battery from 20% to 80% on an 11 kW charger at 90%, that is 36 ÷ 9.9 = 3.64 hours.
Why is there a maximum the car can accept?
The charging power is limited by both the charger and the car's onboard charger or battery. The tool uses the lower of the two, so a 150 kW charger cannot push more than the car takes.
Why does charging to 100% take longer than the tool says?
The tool assumes constant power. Most electric cars slow their charging as the battery fills, especially above about 80%, so the last stretch takes longer. Charging 20–80% is the most accurate use.
What efficiency should I use?
90% is a typical starting assumption for losses in the charger, cable and battery. Home charging in the cold or at low power tends to lose more; check your own meter if you can.