How To Calculate Psu Wattage ((free)) May 2026

Fast, free, good for beginners. Cons: Inconsistent results across calculators (some overestimate by 100W+, others underestimate). OuterVision’s “Expert” mode is decent; basic mode often overshoots. 3. GPU + CPU Rule of Thumb (Quick Approximation) Formula: [ \textPSU Wattage = (\textGPU Max Power + \textCPU Max Power) \times 1.5 ] Then round up to the nearest 50W.

Use an online calculator (OuterVision expert mode) + add 100–150W for modern GPUs or future upgrades. Then cross-check with the GPU+CPU rule. If they differ by more than 150W, trust the higher value. how to calculate psu wattage

Would you like a simplified checklist to calculate wattage for your specific build? Fast, free, good for beginners

RTX 3080 (320W) + Ryzen 9 5900X (140W) = 460W × 1.5 = 690W → recommend 750W. Then cross-check with the GPU+CPU rule

Enter your CPU, GPU, RAM, etc. → they estimate peak load and recommend a PSU wattage.

Buying a PSU that exactly matches the calculated wattage. Always add 20–30% headroom for efficiency, transients, and longevity.