Electrical Energy Calculator
Calculate electrical energy consumed using power and time. E = P × t. Results in joules and kilowatt-hours.
Enter power and time.
Electrical Energy Formula
E = P × t
kWh = Watts × Hours / 1000
kWh = Watts × Hours / 1000
Example: A 100 W bulb running for 5 hours.
E = 100 × 5 = 500 Wh = 0.5 kWh
E = 100 × 5 = 500 Wh = 0.5 kWh
FAQ
What is a kilowatt-hour?
1 kWh is the energy consumed by a 1,000 W device running for 1 hour. It equals 3,600,000 joules. This is what your electricity bill measures.
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Last updated: 2026-08-08