Watt-hour Calculator
Find energy in watt-hours from power and time.
Watt-hours measure energy used — power multiplied by time.
The math behind it
Energy (Wh) = power (W) × time (h). Divide by 1000 for kWh, the unit on your electricity bill.
Worked example
60 W bulb for 5 h → 300 Wh = 0.3 kWh.
FAQ
Wh vs W?
Watts is the rate of energy use; watt-hours is the total energy used.