EV Charging Time Calculator
Find out how long it may take to charge your electric car at home or at a public charging station. Enter your battery details, charger power and charging efficiency to get a personalized estimate in hours and minutes.
Calculate Your EV Charging Time
Complete the simple steps below. The calculator automatically updates the estimated charging duration whenever you change an input.
Charging Calculator
3 EASY STEPSYour Charging Estimate
RESULTSEstimated time to reach your target battery charge based on the entered details.
Results are estimates. Actual charging time may vary because of vehicle charging curves, temperature, charger output and other conditions.
Understand Your Charging Time
Three important factors determine how long your electric car needs to charge.
Battery Energy Needed
Charging from 20% to 80% requires less energy than charging from 10% to 100%.
Charging Power
A higher-power charger can reduce charging time, provided your vehicle supports that power.
Charging Slowdown
Charging power may decrease as the battery fills, especially during DC fast charging.
EV Charging Time Calculator: Formula & Guide
The EV Charging Time Calculator estimates how long it may take to recharge an electric vehicle based on usable battery capacity, charging percentages, charger power and charging efficiency. It also allows you to adjust the assumed average power to account for charging slowdowns.
How Is EV Charging Time Calculated?
First, calculate the battery energy required. Then estimate the electricity needed after accounting for charging losses. Finally, divide that electricity requirement by the assumed average input power.
Worked Example: 60 kWh Battery
- Usable battery capacity: 60 kWh
- Starting charge: 20%
- Target charge: 90%
- Charger power: 11 kW
- Vehicle charging limit: 11 kW
- Charging efficiency: 90%
- Average-power factor: 90%
Energy added = 60 × 70% = 42 kWh. Electricity required = 42 ÷ 0.90 = 46.67 kWh.
Average input power = 11 × 90% = 9.9 kW. Estimated charging time = 46.67 ÷ 9.9 = 4.71 hours, approximately 4 hours 43 minutes.
AC Charging vs DC Fast Charging
AC charging is commonly used at home, work and destination charging locations. The vehicle’s onboard charger may limit how much AC power it can accept.
DC fast charging can provide substantially higher power, but the actual rate depends on the vehicle, battery temperature, battery charge level and charging station.
Why Does EV Charging Slow Down Near 80%?
Many electric vehicles gradually reduce charging power at high battery percentages to protect the battery and manage heat. This is why charging from 80% to 100% can take longer per percentage point than charging at lower battery levels.
What Is the Average-Power Factor?
The average-power factor represents the assumed average charging power as a percentage of the lower of the charger rating and vehicle charging limit.
For example, a power limit of 100 kW with an average-power factor of 70% gives an assumed average input power of 70 kW. This is a simplified approximation rather than a vehicle-specific charging curve.
Factors Affecting Charging Duration
Actual charging time may vary due to battery capacity, starting and target charge levels, charger power, onboard charging limits, battery temperature, electrical supply, charging efficiency and vehicle software.
Charging Time vs Charging Cost
Charging time measures how long a charging session takes, while charging cost measures the amount paid for electricity and fees. A faster charging session is not necessarily cheaper.
Use the EV Charging Cost Calculator to estimate the cost of charging your vehicle.
Additional EV Charging Information
For more information about charging infrastructure and equipment, visit the US Department of Energy Alternative Fuels Data Center .
Related EV & Energy Calculators
Frequently Asked Questions
How long does it take to charge an electric car?
It depends on the energy required, charger power, vehicle charging limits and charging conditions. Enter your values into the calculator to estimate the duration.
How long does a 7 kW charger take to charge an EV?
Adding 35 kWh at a constant 7 kW with no losses would take five hours. Charging losses and reduced average power can increase the time.
Is an 11 kW charger faster than a 7 kW charger?
It can be, provided the vehicle and electrical supply support the higher charging power. The vehicle’s onboard charger may limit the actual rate.
Why does DC fast charging slow down after 80%?
Many vehicles reduce charging power at higher battery percentages to manage battery temperature and operating conditions. The exact charging curve varies by model.
Can I calculate charging time from 20% to 80%?
Yes. Enter 20 as the starting charge and 80 as the target charge. The calculator estimates the energy and charging duration for that range.
Does this calculator support home and public chargers?
Yes. Enter the appropriate charger power and vehicle charging limit for AC or DC charging.
Does the calculator use real-time charger data?
No. Results are based on the values you enter and do not use a live vehicle or charging station connection.