PSU Wattage Calculator
Size your power supply with honest headroom math.
Pick your CPU and GPU (or enter wattages manually), add your accessories, and get a recommended PSU wattage with transparent assumptions — minimum, comfortable, and the retail tier to buy.
Recommendation
Results are estimates for planning — not electrical, engineering, or purchasing advice. Verify against official manufacturer specifications.
One or more selected parts use sample data that has not been re-verified. Check the official spec pages before buying.
PSU tier to buy
750 W
Common retail sizes: 450, 550, 650, 750, 850, 1000, 1200, 1600 W.
Estimated system load
529 W
CPU peak + GPU peak + accessories (117 W)
Recommended minimum PSU
650 W
Estimated load x 1.1 floor, rounded up to a retail size.
Recommended comfortable PSU
662 W
Estimated load x 1.25 for your profile.
Suggested efficiency class
80 PLUS Gold. The 650-850 W range is where Gold units hit the sweet spot of price, efficiency, and quiet operation — this is what most builders should buy.
Safety notes
- These figures are planning estimates based on vendor-published limits, not measurements of your specific parts. Verify CPU, GPU, and PSU specifications on the manufacturers' official pages before purchase.
- PSU quality matters as much as wattage. A reputable current-generation unit at the recommended tier beats an oversized bargain unit every time.
- Never mix modular cables between different PSU brands or models — pinouts differ and mismatched cables can destroy hardware.
- If your GPU uses a 16-pin (12VHPWR / 12V-2x6) connector, seat it fully and avoid tight bends near the plug.
Methodology — Results are estimates for planning — not electrical, engineering, or purchasing advice. Verify against official manufacturer specifications.
Frequently asked questions
How accurate is this PSU wattage calculator?
It is a planning estimate, not a measurement. We sum vendor-published power limits (GPU TGP/TBP and CPU PPT/MTP) plus conservative accessory allowances, then add headroom. Real draw is usually lower, but sizing against the ceiling keeps you safe. Always confirm the final choice against your exact parts' official specifications.
Why does the recommendation round up to a specific wattage?
Power supplies are sold in fixed sizes (450, 550, 650, 750, 850, 1000, 1200, 1600 W). We round the comfortable target up to the next real size so the number you see is one you can actually buy.
What headroom does it add?
The comfortable recommendation multiplies estimated load by 1.25 for standard use, 1.35 for light overclocking, or 1.45 for future-upgrade headroom. The minimum figure uses a 1.1x floor. Headroom covers transient spikes, efficiency, quiet operation, and capacitor aging over time.
Can I use it if my exact CPU or GPU is not listed?
Yes. Switch on the manual entry option for the CPU and/or GPU and type the peak wattage from the vendor's spec page (PPT/MTP for CPUs, TGP/TBP for GPUs). The tool works entirely on the numbers you provide.
Does a higher-wattage PSU use more electricity?
No. A power supply only delivers what the system draws, so a 1000 W unit running a 400 W system draws about the same from the wall as a 650 W unit would. Oversizing mainly wastes money and can slightly reduce efficiency at very low load.