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Power & thermal calculator
Add up component draw, get a PSU size with headroom, the heat the build puts out and the airflow an enclosure needs. CPU and GPU figures are manufacturer-rated peaks; measure your own build for the real answer.
168 W
Peak system draw
450 W
Recommended PSU
37%
Peak load on that PSU
401
Heat output, BTU/hr (sustained)
21
Airflow needed, CFM
343
kWh per year
51.51
Energy cost per year
Breakdown
| CPU (peak) | 88 W |
| Motherboard & chipset | 50 W |
| RAM sticks | 10 W |
| NVMe SSDs | 8 W |
| Fans | 12 W |
How it's calculated
- Recommended PSU = peak draw ร (1 + headroom), rounded up to the next common size. Efficiency peaks around 40โ60% load, and GPU transient spikes can exceed rated board power.
- Heat (BTU/hr) = watts ร 3.412. Essentially all electrical power ends up as heat.
- Airflow (CFM) โ 1.76 ร watts รท ฮT(ยฐC): the air needed to carry that heat away at the chosen temperature rise. Real fans deliver less than their rated CFM against filters.