EV Charging Time Calculator
Estimate how long a home AC charge could take. Account for both the charger and your vehicle’s AC limit, with an editable allowance for charging losses.
Plan a home AC charging session
How to estimate home EV charging time
1. Calculate the energy needed
Multiply usable battery capacity by the charge percentage you want to add. A 60 kWh usable pack going from 20% to 80% needs about 36 kWh in the battery. If the target equals the starting charge, the estimate is zero.
2. Find the lower AC power limit
The car cannot take more AC power than its onboard charger supports, even if the wall charger can supply more. The tool uses the smaller of charger output and vehicle AC acceptance. Enter reduced available power when your charger shares load or is configured below its maximum.
3. Allow for losses and real conditions
Efficiency converts AC input power into estimated battery power. Heating or cooling the battery, cabin preconditioning, background loads and slower charging near a high target can lengthen the session. This simplified estimate does not simulate those processes separately.
The method
Battery kWh needed = usable capacity × (target % − starting %) ÷ 100
Available AC kW = min(charger output, vehicle AC acceptance limit)
Estimated net battery kW = available AC kW × efficiency ÷ 100
Estimated hours = battery kWh needed ÷ estimated net battery kW
Estimated AC energy = battery kWh needed ÷ (efficiency ÷ 100)
Example: A 60 kWh usable battery from 20% to 80% needs 36 kWh. With a 7.2 kW charger, an 11 kW vehicle AC limit and an assumed 90% efficiency, net battery power is 6.48 kW. The estimate is 36 ÷ 6.48 = 5.56 hours, about 5 hours 34 minutes when rounded up to a minute.
Charging Time FAQs
Can I enter a 150 kW DC charger here?
No. This calculator is designed for home or other AC charging and the vehicle’s AC acceptance limit. DC fast charging varies over the battery’s charging curve and with temperature and state of charge. Dividing battery energy by a peak DC rating can materially understate charging time.
What is the difference between kW and kWh?
kW measures power, or how quickly energy is supplied. kWh measures energy, or the amount stored or delivered. Battery capacity is entered in kWh; charger output and the vehicle AC limit are entered in kW.
Is 90% charging efficiency accurate for my car?
It is only an illustrative starting assumption. Efficiency can vary by vehicle, charging power, temperature and other loads. Use measurements or manufacturer information that matches your setup. The estimate applies the chosen efficiency once.
Can I estimate an ordinary household outlet charge?
Yes, if you know the available AC charging power and enter it in kW. Check the vehicle and charging-equipment documentation for appropriate use. This calculator does not assess electrical-circuit capacity, installation, wiring or safety.
Why could the car finish later than this estimate?
Actual charging power can change during the session. Battery conditioning, cold or hot weather, load sharing, charging schedules, interruptions and high-state-of-charge taper can add time. Treat the result as a planning estimate and check the vehicle’s own charging forecast.
Background: Natural Resources Canada: electric vehicle charging. Reviewed October 4, 2026. Use vehicle and charging-equipment specifications for your inputs.