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
- Enter your CPU TDP in watts.
- Enter your GPU TDP in watts.
- Enter number of RAM sticks, drives, and fans.
- Click Calculate to get estimated wattage and PSU recommendation.
Use Cases
- •Selecting a power supply for a new PC build.
- •Checking if existing PSU supports an upgrade.
- •Planning power requirements for server builds.
- •Estimating electricity costs for a workstation.
Formula
Total = CPU TDP + GPU TDP + RAM × 5W + Drives × 10W + Fans × 3W + 50W (system). Recommended PSU = Total × 1.2 (headroom).
Frequently Asked Questions
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.