PSU Wattage Calculator

Estimate the power supply your PC needs — total up CPU, GPU, drives and peripherals, then get a recommended wattage with headroom.

Recommendation = total × 1.3 headroom, rounded up to the nearest common PSU rating. This is an estimate — use an inline wattmeter for exact numbers.

Recommended PSU
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Why headroom matters

A power supply runs most efficiently at 40–80% load. Oversizing slightly keeps it quiet and cool.

Transient spikes

GPUs can draw double their rated power for milliseconds — headroom prevents shutdowns.

Efficiency

80 Plus Platinum/Gold units stay above 90% efficiency between 20–100% load.

Future upgrades

A little extra wattage today saves a PSU swap when you upgrade the GPU later.

Common PSU ratings

Match your build to a widely available rating:

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