Determining Total Power Consumption For A system

Thread Starter


Joined Dec 29, 2010
Lately I realized that I need to be able to understand the total power my projects would consume? Are there any techniques to find out how much power a system is consuming (e.g. power drawn by a 5V voltage regulator and power drawn from a DC motor system)?


Joined Oct 23, 2010
Measure the DC voltage applied to your project and the DC current flowing to your project and multiply those two values together.

P=V x I = total power consumed by your project.


Joined Dec 26, 2010
If the system has yet to be built, its power consumption can of course be estimated: how accurate an estimate you will get will depend on the quality of any assumptions it is based on, including things like component efficiencies which can vary between different types.


Joined Mar 14, 2008
If you want the AC power the system uses, the easiest way is to buy a power meter such as the Kill A Watt. It measures voltage, frequency, power, VA , power factor, and total energy used over time.