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Instant result
Enter the data and press the button to do the calculation.
Online Calculator
Electrical energy calculator
Enter power in watts and time in hours to calculate the energy consumed or delivered.
Information
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Local processing
The values are processed directly in your browser.
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Free
No registration, external API or subscription required.
Frequently asked questions
What's the formula?
E = P × t.
How many Wh does 1000 W consume over 2.5 hours?
2,500 Wh.
How many kWh is 2,500 Wh?
2.5 kWh.
How do you convert Wh to joules?
Multiplying by 3,600.