PC Power Supply Calculator | PSU Wattage Calculator

PC components

Enter the estimated maximum wattage for each component. Leave unused entries at 0 W.

W

RECOMMENDED PSU

550 W

Includes approximately 25% power headroom

ESTIMATED SYSTEM DRAW 425 W / 550 W

Component total 425 W

Headroom 25%

Target capacity 532 W

            
                Recommended PSU size
            
                550 W

PSU load at estimated maximum 77%

PSU wattage is only part of choosing a power supply. Check the power requirements and connector requirements specified by your CPU, graphics card and other component manufacturers before buying or installing a PSU.

Common PSU sizes

The nearest suitable standard capacity is highlighted.

400 W

450 W

500 W

550 W

600 W

650 W

700 W

750 W

800 W

850 W

1000 W

1200 W

How the PC power calculator works

Enter the estimated maximum power consumption of your PC components in watts.

The calculator adds the components together to estimate the system's maximum power requirement. It then adds 25% headroom and rounds the result up to a commonly available PSU capacity.

Why add PSU headroom?

A power supply should not normally be selected with a rated capacity identical to the calculated system requirement. Extra capacity provides room for variations in component power use, additional devices and future upgrades.

What wattage should I enter?

Where possible, use the power figures supplied by the component manufacturer. For graphics cards in particular, check the manufacturer's recommended PSU, power consumption and required power connectors.

General estimate only: This calculator cannot account for every transient power spike, PSU design, efficiency characteristic, connector requirement or individual hardware configuration. Always check the requirements of the actual components being used.