Formula
Electrical power for a steady voltage and current is:
Watts = volts × amperes
The electrical-power page uses voltage and resistance instead. The Ohm's law page can show watts beside a solved circuit, but this page only multiplies voltage and current.
Assumptions
- Voltage and current are the values at the same component.
- The values are steady, not a waveform.
Worked example
12 V at 2 A is 24 W.
Input definitions
- Voltage
- The potential difference, in volts.
- Current
- The current, in amperes.
Limitations
This is a classroom calculation. It is not a laboratory procedure, a wiring plan, or a measured instrument reading.
Questions
What if I know resistance instead of current?
Use the electrical-power page. It divides voltage squared by resistance.
Is this mechanical power?
No. Joules per second from work and time are on the physics power page.