PSU Wattage Calculator
Add up your GPU, CPU and everything else, then size a power supply with real headroom — not one that just barely covers today's build. Enter your own components' rated wattage below.
PSU Wattage Calculator
Enter your own components' rated wattage (from the box or spec sheet) — this doesn't assume any specific product's power draw.
375W
total system draw
550W
recommended PSU tier
Based on your 375W total plus a 30% headroom margin (≈488W) — headroom protects against power spikes and leaves room for future upgrades, not just today's build.
See real 550W-class power supplies with honest buying criteria.
Read the PSU Buying GuideEstimate only — always check your GPU manufacturer's minimum PSU recommendation too
Why headroom matters
Modern GPUs can have brief power spikes well above their average draw, and a PSU running near its max capacity constantly runs hotter and less efficiently. Full buying criteria — efficiency ratings, connector types, modular vs. non-modular — are in our PSU buying guide.
Frequently Asked Questions
How much headroom does the calculator add?
It adds a safety margin above your components' combined rated draw to absorb momentary power spikes and leave room for future upgrades — see the exact figure in your result.
Where do I find my GPU and CPU's rated wattage?
Check the manufacturer's official spec page for your exact model rather than guessing — TDP ratings vary significantly even within the same product line.