PSU Wattage Calculator — SpecClear

PSU Wattage Calculator

Select your components and we’ll tell you exactly what power supply you need — with specific product recommendations at each tier.

Approx. 2.5W per DDR5 stick

Approx. 5W per NVMe drive

Approx. 10W per HDD

Approx. 2W per fan average

Higher ratings waste less electricity and run cooler. Gold is the right choice for most gaming PCs.

RECOMMENDED PSU SIZE
W

PSU OPTIONS AT THIS WATTAGE

How we calculate this: We add the TDP of each component, apply a 20% system overhead for transient spikes and capacitor aging, then divide by your chosen PSU efficiency rating to find the minimum wall-draw capacity needed. We then round up to the next standard PSU size. Running a PSU at 50–70% of its rated capacity keeps it in the efficiency sweet spot and extends its lifespan. The wattage shown is the minimum safe size — buying one tier higher is never wrong.

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