PSU Calculator

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If you’re working on your own PC build, knowing what power supply you need is an important step. Our PSU Calculator helps you do just that, without all the usual hassle. Just enter all your components into the calculator below and it will work out what PSU  you need for your build – simple as that.

Disclaimer: All efforts have been made to ensure the accuracy of all information provided by this calculator. WePC assumes no liability, expressed or implied, for any issues that might arise from the power supply suggested by the PSU Calculator.

Why use a Power Supply Calculator?

If you’re new to PC building, the chances are, your knowledge of components wattage is going to be fairly limited. Using a PSU calculator is going to take any of the stress that comes with choosing the right PSU away from the build process. It not only recommends the required wattage for your build, but it also offers up some of the best PSU options for each specific price point. The PSU calculator really does make your life a whole lot easier. 

How Your PSU Can Affect Gaming Performance

The most important components in a gaming PC are the CPU and GPU. But these components, just like all the others, need adequate power to operate. If your power supply can only provide 80% of the power your GPU needs, it can’t just simply run at 80% performance. Instead, the system will be unable to run at all and will likely crash.

So, if you’re working with a PSU that can’t support the rest of your build, all that hard work you put into building your gaming PC will be for nothing.

But, that’s not all. If you’re working with an unstable power supply, you run the risk of damaging your components permanently. That’s why we always recommend choosing a PSU that has a higher efficiency rating.

Upgrading Your PSU

One thing to remember, as with all PC components, you can always choose to upgrade your PSU. If you ever choose to upgrade your GPU, upgrading your PSU should be a priority too. You need to make sure you’re giving your GPU as much power as it needs to run properly, and you might even need to provide more PCIe power connections than your current PSU can provide – depending on the model.

But, don’t worry, upgrading your PSU is fairly simple. You just need a screwdriver, some cable-management love, and patience. If our PSU calculator has told you that you need to upgrade, then all you need to do is follow these simple steps.

  1. Shut off power to your PC and remove the power cord
  2. Remove the side panel of your PC case to gain access to all the technical goodies inside
  3. Remove all PSU power cables and connections from your components
  4. Remove any other components that are obstructing your access to the PSU
  5. Remove the screws on the back of the PC that attach the power supply to the case and remove the entire power supply unit
  6. Once you’ve safely disposed of your old PSU, place your new, upgraded PSU into position
  7. Screw your new PSU in and put back any other removed components
  8. Reattach all the power cables so your PSU is properly installed
  9. Power on your PC to check all the connections are working
  10. Turn your PC back off, reattach the side panel and enjoy your new PC build

Frequently Asked Questions (FAQs)

How do I calculate my PSU requirements?

The best power supply for your PC build is the one that provides the right amount of wattage to all components simultaneously. Manually calculating this requires that you multiply the total amps of all components by the total volts of all components. The result is the total watts that your PC build requires. If you input all the components of your PC build into our calculator, it will do this for you and provide a list of options.

Why should I use the calculator to find a power supply?

The power supply provides power to every component and if you install the wrong power supply, you could damage the components. The right PSU will provide all your components with a consistent amount of energy when they need it.

What are some of the top PSU brands that I can buy?

Top brands include:

  • Corsair
  • EVGA
  • Rosewill
  • Seasonic
  • Cooler Master
  • Silverstone
  • FSP
  • Thermaltake

However, you need to select the PSU that’s right for you so consider all options before purchasing.

How do I know that the PSU is the right size?

Every PC case has a space for the power supply unit although space may vary in size and shape. For example, small form factor cases will not be able to accommodate a PSU meant for a mid or full tower case. It is always best to look at the dimensions of your PC case and make sure that you are buying a power supply unit that can fit in the designated space.

Where can I get news about power supplies?

Our news section is a great place to get information about the latest and greatest in tech. Click the link below for all the latest news and information.

Read More PSU News, Guides and How To’s

How do I know which power supply to buy?

Before you decide what power supply to buy, it is crucial that you know all the components that you currently have within your build or the ones that you would like to include. Here’s a complete list of items that you need to consider when calculating your power supply needs.

  • Motherboard – Be sure you know what kind of motherboard (Desktop, Server, Laptop, etc.) your build currently has or what form factor you want to put in your new build. This is a critical component of your calculations because almost everything within your build plugs into and derives power from the motherboard.
  • Central Processing Unit (CPU) – Be sure you know the make, model or series, and socket size.
  • Graphics Processing Unit (GPU) – You will need to account for the actual power draw and the number of additional power pins a GPU may have. It’ll be either 6, 8, 6+6, 6+8, or 8+8-pins – and that’s per GPU. So make sure your PSU has enough cable to support that. Most PSUs will have at least one cable that is compatible with either an 8-pin or a 6-pin connector.
  • Memory (RAM) – Always know the number of memory sticks that your motherboard can support as well as the size (GB) of each one. Optical Drive – If your PC build includes an optical drive, be sure to include this in your calculations. Also make sure that you know the optical media type (Blu-ray, CD-ROM, etc.) of your optical drive.
  • Hard Drives (HDD) – You need to know the size (inches) and RPM (e.g. 7200RPM) of each hard drive that you currently have within your build or that you would like to include.
  • Solid State Drive (SSD) – You need to know the size (GB) of each solid-state drive that you currently have within your build or that you would like to include. Remember that sometimes these can be attached to the motherboard.
  • Fans/Peripherals – You may want to include add-ons like a sound blaster card or RGB case fans. These devices also draw a small amount of power so err on the side of caution by rounding up power wattage to accommodate peripherals.

What is the 80 PLUS Certification?

80 PLUS is a certification that measures the power supply’s efficiency. Manufacturers will voluntarily send their products to an independent lab to test the power supply’s energy efficiency at different loads. Based on the results, PSUs are given one of 6 levels of certifications: 80 PLUS, 80 PLUS Bronze, 80 PLUS Silver, 80 PLUS Gold, 80 PLUS Platinum, or 80 PLUS Titanium.