I have to calculate the power of my square (actually rectangular :D) wave signal, and then the energy of it. I have amplitude, current, duty cycle, and frequency parameters.

For example:
Amplitude: 2.5 V
Current: 3.47 A
Duty Cycle: 70%
Frequency: 10 kHz

In my opinion, the average power P = V·I·Duty Cycle, but I don't know energy (E = ?).

How can I calculate the power and energy of my square wave signal?

I have checked Trever_G's answer on this link but I wasn't satisfied or not sure or maybe I didn't understand the formula: How to calculate the average power for a square wave DC signal

  • \$\begingroup\$ You are correct with your first equation. However, in order to be able to calculate the total energy spent you need to know how long the circuit is energized. Do you mean "How much energy is delivered within one single wave ? ". If so the single wave would last only 100uSec. Knowing the power you know how much energy is spent during one second. In 100uSec the total energy would be 1/10000 x the calculated power. \$\endgroup\$ Jan 5, 2023 at 21:11
  • 1
    \$\begingroup\$ Sir Fred, thank you so much for your helps. The explanation is good enough for me. \$\endgroup\$ Jan 5, 2023 at 21:26

1 Answer 1


In my opinion, the average power P = V·I·Duty Cycle

Correct if we are talking about a waveform with peak voltage and current of those stated and the waveform returns to zero in the non-active part of the duty cycle.

but I don't know energy (E = ?).

It is power × time.

So, your power is 2.5 × 3.47 × 0.7 = 6.0725 watts and, in one second it passes 6.0725 joules to the load. In 10 seconds it passes 60.725 joules to the load.

Frequency has nothing to do with it.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.