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Power Supply Calculator
Add your component loads and calculate a PSU output target with 30% headroom.
Choose models or enter wattages
Search this starter catalog of 39 desktop CPU/GPU models. Selecting a published power rating fills the load below. Manual example values are used until you select your parts.
Manual entry. Search and choose a model to use its published rating. Other models and custom configurations remain editable.
Manual entry. Search and choose a model to use its published rating. Other models and custom configurations remain editable.
Other component loads
Replace these illustrative manual totals. If you itemize all your storage or cooling below, set that group here to 0 to avoid double-counting.
Itemized storage, cooling & accessories
Add exact models or a custom HDD, RAM module, PCIe card, pump, or USB device. These loads are added to the totals above: subtract anything already counted there. Exclude separately powered monitors and network equipment.
Your power budget
- Component load
- 480 W76.9%
- 30% headroom
- 144 W23.1%
- PSU floor / rounding
- 0 W0%
The higher of component load + 30% and the documented system PSU minimum, rounded up. Headroom is 30% of component load, not 30% of this ring.
480 W × 1.30 = 624 W
Documented system PSU minimum: not specified
Published ratings are not live measurements or guaranteed transient peaks. Verify your exact board, BIOS limits, PSU connectors, rails, and manufacturer requirements.
Catalog review: 2026-09-16. Updates only on request; not a live parts feed.
Where the power goes
Share of your 480 W component load, before headroom.
Compare PSU capacities
These listed capacities meet the calculated wattage target. Bars show component load, the 30% allowance, and capacity beyond that allowance.
650 W
73.8% modeled load170 W above component load.
700 W
68.6% modeled load220 W above component load.
750 W
64% modeled load270 W above component load.
Capacity examples, not product or efficiency recommendations. Check connectors, rails, form factor, transient response, and exact component requirements.
Model ratings, manual overrides, and catalog updates
The tool adds your component loads, then adds 30% of that total. This is a chosen planning margin, not a universal PSU requirement and not a claim that 30% of the final PSU rating remains unused. The greater of a selected GPU’s system PSU minimum and your manual documented minimum is a separate lower bound, not a component load.
Intel entries use published maximum turbo power. NVIDIA entries use reference total graphics power; AMD graphics entries use typical board power. These are different rating types, not measured wall-socket usage or promises about short power spikes. Check the exact board partner and BIOS limits.
AMD CPU entries currently verify default TDP only. Their wattage field is intentionally left empty until you enter a verified package/socket power budget. A thermal rating is not silently promoted to an electrical maximum. Other component groups remain manual; this catalog is not exhaustive and does not check socket or connector compatibility.
Changing a filled-in load creates a manual override while preserving the source rating for comparison. Sources and verification dates are shown with each selected model. Entries more than 90 days old receive a review notice; that notice does not change the data.
Updates happen only when requested. The reviewed catalog is bundled with the static site and works without live vendor requests. A refresh checks the original sources, changes verified records, and rebuilds the local pages. Nothing is automatically published.
This is DC output sizing, not wall consumption. Include conversion losses, drive spin-up, and accessories without counting the same load twice. Reference: Intel’s power-supply selection guide.
Calculated in your browser. Inputs and files aren’t uploaded or saved. Tool sources & licenses