EV charging time calculator
Estimate EV charging time from battery size, state of charge, charger power, and charging efficiency.
What this calculator covers
Use this EV charging time calculator to estimate how long a charging session may take across a chosen state-of-charge window.
Frequently asked questions
- What charger power should I enter for a Level 1, Level 2, or DC fast charger?
- A standard Level 1 outlet delivers around 1.4 kW, a typical Level 2 home charger is commonly 7.2 kW or 11.5 kW, and DC fast chargers range from roughly 50 kW to over 350 kW depending on the station and your vehicle's onboard acceptance limit. Enter the lower of the station's output and your car's maximum charge rate.
- Why does actual charging take longer than the estimate near a full battery?
- Real EVs use a charging curve that tapers the rate as the battery approaches full charge to protect battery chemistry. This calculator applies a constant efficiency percentage across the whole session, so it will underestimate time when charging above roughly 80% state of charge.
- What is "effective charging power" in the result?
- Effective charging power is the charger's rated output reduced by the charging efficiency percentage. Because some power is lost to heat and conversion in the charger and battery system, the battery fills at a lower net rate than the charger's nameplate rating.
- How do I estimate an overnight charge from near-empty to 80%?
- Enter your battery capacity, set the current state of charge to your typical arrival level, set the target to 80%, and use your home charger's power rating. The result gives a rough session length you can compare against the hours available before you need the vehicle.
Tool
Run the calculation
Result
RESULT · CHARGING TIME
â„–187
Primary result
6.94 hours
Charging from 20% to 80% on a 7.2 kW charger takes about 6.94 hr after applying 90% charging efficiency.
- Battery energy added
- 45 kWh
- Wall energy drawn
- 50 kWh
- Effective charging power
- 6.48 kW
- Charging time
- 6.94 hr
Step-by-step solution
- 1.Find the battery energy that must be added: (80 - 20)% of 75 kWh = 45 kWh.
- 2.Apply charging efficiency to the charger power: 7.2 kW × 90% = 6.48 kW effective charging power.
- 3.Divide the battery energy needed by the effective charging power to estimate 6.94 hr.
Walkthrough
Visual walkthrough
EV charging time depends on how much battery energy must be added and how much of the charger power actually reaches the battery after efficiency losses.
01
Measure the charge-window energy
45 kWh
The state-of-charge change determines how much of the pack must be filled during this session.
02
Reduce charger power by efficiency
7.2 kW × 90% = 6.48 kW
Not all wall power becomes battery energy, so the effective rate is lower than the charger nameplate rating.
03
Read the charge time
Battery energy needed divided by effective charger power gives the session duration estimate.
6.94 hr