(CPU Max Draw + GPU Max Draw + 100W for system) × 1.5 = Ideal PSU Wattage
Remember: A high-quality 750W PSU will outperform a garbage 1200W PSU every single time. Calculate carefully, buy from a reputable brand, and your PC will have stable, clean power for a decade. The heartbeat of your machine depends on it. how to calculate pc power supply
Then, add 100W to that result for future upgrades and capacitor aging. (CPU Max Draw + GPU Max Draw + 100W for system) × 1
Do not buy a PSU where your maximum load exceeds 80% of the PSU's rating. Conversely, do not buy a PSU where your idle load is below 10% of the rating. buy from a reputable brand