Power Supply Calculator
Newegg's Power Supply Calculator (or PSU Calculator) helps you quickly find all the compatible power supplies for your current or future PC build. We're here to help you make sure that you consider all the important elements of your search before you purchase the right power supply!
Choose your Components
Frequently Asked Questions
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.
How do I know that the PSU is the right size?
Every PC case has a space for the power supply unit although the 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?
Newegg Insider is a great place to get information about the latest and greatest in tech. You can check out articles like "The FSP Hydro PTM+ is a water-cooled power supply with RGB lights" or "Future-Proofing 101 – Cases and Power Supplies."
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.