Computer PSU Wattage Calculator

Calculations Made Simple For Quick Power Supply Selection

Power Supply Wattage Calculator









* Calculations are rounded off for more accessible power supply selection. An extra 10% headroom is also added.

Find the Right Power Supply for Your PC

Our Computer PSU Wattage Calculator is designed to help you determine the exact power supply unit (PSU) your computer needs. Whether you’re building a gaming rig, upgrading your existing system, or optimizing a custom build, choosing the right PSU wattage is crucial for performance and stability.

How to Use the Computer PSU Wattage Calculator

Using the calculator is simple:

  1. Select Your Components – Choose the categories for your CPU, GPU, cooling system (air or water), and the number of SSDs and HDDs in your build.
  2. Enter the Number of Components – If you have more than one CPU or GPU, adjust the input fields accordingly.
  3. Calculate – Click the “Calculate” button, and the tool will provide a recommended PSU wattage, including a 10% safety buffer for reliable performance.

Why It Matters

Getting the right PSU wattage is essential to avoid power issues. Undershooting your wattage requirements can lead to crashes or reboots, while overshooting can result in energy inefficiency. By using our tool, you ensure that your system has the appropriate power supply based on your specific hardware.

Power Supply Tips:

  • Always Plan for Future Upgrades – If you plan to upgrade components later, it’s worth choosing a PSU with some extra capacity.
  • Efficiency Matters – Look for PSUs with 80 Plus certifications for better energy efficiency and reduced heat generation.
  • Compatibility – Ensure your PSU fits your case and has the necessary power connectors for your GPU and other components.

Now that you understand how crucial the right PSU wattage is, go ahead and use the calculator to get the right recommendation for your build.

How to Optimize Your Power Supply Selection

Once you get your wattage recommendation, consider the following:

  • Form Factor: Ensure the PSU physically fits inside your PC case. Standard sizes include ATX and SFX.
  • Modular vs. Non-Modular: A modular PSU allows you to only connect the cables you need, which helps with cable management.
  • Brand Reputation: Choose a reliable PSU brand like Corsair, Seasonic, or EVGA to ensure long-term durability and stable power delivery.

If your PSU doesn’t supply enough power, your computer may not boot, or you could experience random shutdowns during heavy loads.

The 10% headroom ensures your PSU isn’t running at full capacity, which increases longevity and stability.