PSU Calculator

How the calculation works

We add the card's board power, the CPU's maximum power (Intel Maximum Turbo Power, or AMD's socket power limit of 1.35 × default TDP) and about 75W for the other parts. Dividing so the supply runs at no more than 80% of its rating gives the parts-based estimate.

If the card maker publishes a recommended power supply, we take whichever is larger and round up to a common rated size (450W, 500W, 550W and so on). For CPUs whose maximum power we couldn't confirm, we use the card maker's recommendation alone.

How to check your current power supply

Most power supplies can't report their capacity to Windows or any app. Open the side panel and read the rated output (W) on the power supply's label, or look up the model name from your order history on the maker's site.

If the label lists both rated and peak output, compare the rated output with the figure above. Shut down and unplug the power cable before opening the side panel.

Also check when choosing a power supply

• Look at the rated (continuous) output. Some products put their peak output in the name, so check that the rated output in the full specs meets the figure above.
• Make sure the power supply has the auxiliary power connectors your graphics card needs (8-pin, 12V-2x6 and so on).
• An 80 PLUS rating describes efficiency (how little power is wasted), not capacity.