To calculate the wattage your PC needs, you must account for the peak power draw of your individual components and add a safety buffer to handle "transient spikes." In 2026, the standard recommendation for a stable system is to find your total estimated draw and add at least 20–30% of "headroom." 1. Identify Component Peak Draw
The Method: Inputting your specific parts list into a web tool that has a database of actual draw numbers. how to calculate psu wattage