EV charging time calculator
How long a charge takes at a given amperage, and what amperage you need for an overnight charge.
Estimate time from energy and power, or the AC power needed within your available time. Use the vehicle's usable battery capacity where known. Results stay on screen without an email address.
How the arithmetic works
Battery energy = capacity × (target percentage − starting percentage) ÷ 100. Supply energy = battery energy ÷ efficiency. AC power in kW = voltage × charging current ÷ 1,000. Time = supply energy ÷ the lower of supply power and the vehicle's AC limit, when known. Required AC supply power = supply energy ÷ available hours.
For a 75 kWh usable battery from 20% to 80%, battery energy is 45 kWh. At 90% efficiency, supply energy is 50 kWh. At 240 V and 32 A, supply power is 7.68 kW, giving about 6.51 hours if the vehicle accepts that power.
What the estimate can tell you
It helps compare charging plans. It does not approve an outlet, circuit, panel or installation. This tool supports AC Level 1 and Level 2 planning only. Power alone does not identify AC versus DC charging, and a constant-power calculation is not a DC charging curve.
Read charging levels, panel capacity questions, and the installation readiness planner.
Sources and assumptions
The equations use energy and power units. The efficiency choices are disclosed planning assumptions, not measured efficiency for your car. The Department of Energy describes AC/DC levels, equipment and charging-time factors: AFDC charging infrastructure. Technical scope checked October 13, 2026.
Ready to get a charger installed?
Send your property type and ZIP code, and a licensed installer for your area gets in touch.
