Science & engineering
DC electrical power calculator
Relate voltage and current to power and energy over time.
A clear answer. Here’s how.
For steady direct current, P = VI. Energy = power × duration; shows watt-hours, kilowatt-hours and joules. Uses voltage and current magnitudes and assumes they remain constant. AC power factor and waveforms are excluded.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Voltage magnitude (V)
- 12
- Current magnitude (A)
- 2
- Operating time (hours)
- 3
Example result
- Power (W)
- 24
- Energy (Wh)
- 72
- Energy (kWh)
- 0.072
- Energy (J)
- 259,200