OhMyCalc

PSU Wattage Calculator

Calculate estimated power consumption and recommended PSU wattage for your PC build. Enter CPU TDP, GPU TDP, RAM, drives, and fans to get a sizing recommendation.

How to Use the PSU Wattage Calculator

  1. Enter your CPU TDP in watts.
  2. Enter your GPU TDP in watts.
  3. Enter number of RAM sticks, drives, and fans.
  4. Click Calculate to get estimated wattage and PSU recommendation.

使用场景

公式

Total = CPU TDP + GPU TDP + RAM × 5W + Drives × 10W + Fans × 3W + 50W (system). Recommended PSU = Total × 1.2 (headroom).

常见问题

Why add 20% headroom?
PSUs run most efficiently at 50–80% load. 20% headroom ensures efficiency and longevity under peak load.
What is TDP?
TDP (Thermal Design Power) is the maximum sustained power a CPU or GPU consumes under load.
Should I get a modular PSU?
Modular PSUs allow you to connect only needed cables, improving airflow and cable management.