kWh = kW × hours
Convert watts to kilowatts by dividing by 1,000
kWh = (watts ÷ 1,000) × hours
Convert amps and volts to watts if needed: watts = amps × volts
Then calculate kWh using: kWh = (amps × volts × hours) ÷ 1,000
For multiple devices, calculate each device’s kWh and add them together
To find cost, multiply kWh by the electricity rate per kWh