Amps to kWh Calculator
Calculate energy from current (amps), voltage, and time.
kWh = (Amps × Volts × Hours) ÷ 1,000
Formula
A
V
hours
—
Enter values above
How This Formula Works
Power (watts) = amps × volts. Multiply by time to get watt-hours, then divide by 1,000 for kWh. This is exactly how your home EV charger works: a 40A charger on a 240V circuit delivers 9,600W (9.6 kW). Over 8 hours, that's 76.8 kWh — enough to charge most EVs from near-empty. The formula is fundamental to understanding both home charging costs and EVSE sizing.
Common EV Examples
40A Level 2, 8 hours
40A × 240V × 8 hrs
76.8 kWh
48A Level 2, 7 hours
48A × 240V × 7 hrs
80.6 kWh
12A Level 1, 12 hours
12A × 120V × 12 hrs
17.3 kWh (~60 mi)
80A Level 2, 6 hours
80A × 240V × 6 hrs
115.2 kWh
32A Level 2, 6 hours
32A × 240V × 6 hrs
46.1 kWh
16A (EVSE cord), 10 hrs
16A × 240V × 10 hrs
38.4 kWh