Here’s the cold, hard truth:

You plug in your parts (CPU, GPU, RAM, drives, fans, liquid cooling pumps), and the calculator spits out a number: “Recommended PSU Wattage: 650W.”

Your PSU is the heart of your PC. If it fails, it can take your motherboard, CPU, and GPU with it. Spending an extra $40 today on a higher-wattage, high-quality unit is the cheapest insurance policy you will ever buy for your rig.

You’ve picked out the perfect CPU. You’ve secured a graphics card that can handle anything at 1440p. The RGB RAM is ready to glow. But there’s one component that most new builders leave as an afterthought: the Power Supply Unit (PSU).

Most power supplies are most efficient at 40–60% load . A calculator helps you hit this "sweet spot" to save on electricity bills.