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PETME
Bench tool

PSU calculator

Choose a processor and graphics card, then add drives and fans. The calculator shows the total, the headroom and which numbers they came from – each is either a maker’s figure or our clearly marked assumption. The result is an estimate, not a measurement.

Checked:

Headroom
For short spikes, PSU ageing and quieter running.

Result

Recommended PSU wattage (estimate)–

Breakdown of the estimate. “Maker” = a figure from the specification, “Assumption” = our rough value.
ItemWOrigin of the figure

How it calculates

The calculator adds up the processor’s and graphics card’s maximum power draw according to their makers, adds rough assumptions for the other parts, adds your chosen headroom and rounds up to the nearest 50 W.

  • Processor: we do not use TDP, but the maximum power draw. For Intel this is the Maximum Turbo Power from Intel ARK. For AMD with a TDP of 170 W we used the 230 W PPT limit that AMD announced for the AM5 socket. For a TDP of 65 W, AMD does not give the PPT on the product page – we used the same ratio (× 1.35) and mark it as an assumption in the table.
  • Graphics card: Total Graphics Power (NVIDIA) and Typical Board Power (AMD) from the official specifications of the reference cards. Partner cards may draw more – enter a custom value.
  • Everything else: motherboard 50 W, RAM module 5 W, SSD 8 W, HDD 10 W, fan 3 W, USB peripherals 15 W. These figures are our rough assumptions, not makers’ data.
  • Graphics card maker: NVIDIA and AMD state a recommended PSU wattage for the whole system (NVIDIA: for a PC with a Ryzen 9 9950X). If it is higher than our estimate, go with theirs.

The calculator does not assess PSU quality or connectors. Check the graphics card connectors in the compatibility check.

Everything is worked out in your browser. Nothing is sent anywhere and nothing is saved, not even in browser storage.

Notes and sources

  1. AMD: AMD Ryzen 9 9950X – specifications (TDP 170 W, AM5, DDR5)
  2. AMD: AMD Ryzen 7 9700X – specifications (TDP 65 W, AM5, DDR5)
  3. Intel: Intel Core Ultra 9 285K – specifications (FCLGA1851, DDR5, PBP 125 W / MTP 250 W)
  4. Intel: Intel Core i9-14900K – specifications (FCLGA1700, DDR5 and DDR4, MTP 253 W)
  5. NVIDIA: GeForce RTX 50 comparison – TGP, recommended PSU wattage, connectors
  6. AMD: AMD Radeon RX 9070 XT – specifications (TBP 304 W, recommended PSU 750 W)
  7. Hardware Busters (analysis of the Intel specification): ATX v3.1 & PCIe CEM 5.1 – the 12V-2×6 connector (secondary source)

We opened every link above and compared the figures on 12 October 2026. The pages belong to their publishers and can change after that date.