How to Check Power Supply Wattage on Windows 11/10 PC

Published by Nyau Wai Hoe - Updated on

Windows 11 and Windows 10 have a bunch of tools to check how your computer is doing, but figuring out how much power the power supply can handle is tricky. That’s because software can’t directly tell you this since it’s all about the hardware. But don’t worry, we’ve got some tips to help you guess how much power your computer uses without having to open it up.

Also see: How to check RAM type DDR3, DDR4 or DDR5 in Windows 11/10

How to Check Power Supply Wattage on Windows 11 or 10 PC

Why can’t software tell me my PSU’s wattage?

Software is great at giving us a peek into what’s going on inside our computers, like checking temperatures or how much storage we’re using. But when it comes to the power supply’s wattage, things get a bit hazy. Here’s why:

  • The wattage of a PSU is a fixed thing – it doesn’t change like how hot your CPU gets or how full your disk is. Because it stays the same, there’s no sensor inside to constantly check it and tell your computer what’s up.How to tell my Power Supply Unit Wattage
  • Unlike other parts of your computer, PSUs don’t have sensors to send info back to the software. They just give power as needed without much fuss about reporting what they’re doing.
  • Adding fancy sensors to PSUs to tell us their wattage could make them more expensive and complicated, and since you can just look at the label to find out, it’s not something many makers think is worth the trouble.

Useful tip: Check PC hardware manufacturer & model via WMIC in CMD

Can you access the case? Check the Power Supply Unit label

Even though we’re trying to find ways to avoid opening your computer, if you’re okay with it, checking the PSU label is the best way to know its wattage.

  • Most computers have a special place for the PSU, and it’s where you plug in the power cord. It looks like a box.Opening the computer case
  • To see the label, you might have to take off the side panel or peek through a vent, depending on your computer.Check PSU Wattage by opening PC case
  • On the label, you’ll find lots of info, but what you’re looking for is the max power output in watts – that’s your PSU’s wattage.Check Power Supply Wattage on PC
  • Just remember to be safe:
    • Make sure your computer is off and unplugged before you start poking around.Unplug the computer
    • Use something to keep static electricity away so you don’t accidentally fry your parts.
    • If you’re not sure about opening up your computer, maybe ask a friend who knows their way around PCs.
  • While online calculators and software guesses are helpful, nothing beats seeing the info right on the PSU’s label for knowing exactly what you’re working with.

But, only open your computer if you’re comfortable with it and can do it safely.

Linked issue: Why are my PC case fans not spinning?

Checking power consumption of key components

Another way to figure out your PC’s power needs is by seeing how much power the big parts like your CPU and GPU use.

  • For CPUs and GPUs, there are tools like HWMonitor and GPU-Z that show you how much power they’re using right now.How to check power supply on PC Windows 11 or 10How to check PSU wattage without opening computer
  • Remember, these numbers change depending on what you’re doing at the moment.
  • Don’t forget, other stuff in your computer like RAM, hard drives, fans, and things you plug in also use power.

Related resources:

Estimating total power requirements

To really get a good idea of what your PC needs in terms of power, adding up everything and then throwing in a little extra for good measure is a smart move.

  • Online tools like “be quiet! PSU Calculator”, “Newegg Power Supply Calculator”, and “PCPartPicker” are great for getting an estimate. Just plug in what parts you have, and they’ll do the math for you.
  • It’s a good idea to add about 20% more to whatever number you get. This way, your power supply isn’t maxed out all the time, which is better for its health and longevity.
  • If your calculations show that you’re close to or over what your power supply can handle, it might be time to think about getting a bigger one.

Software to check power supply wattage on PC

Related concern: Why is my memory usage so high when nothing is running?

External power meters: A direct measure of power draw

Sometimes, the best way to figure out how much power your computer is using is to measure it directly from the wall.

  • A gadget like the “Kill A Watt” lets you see exactly how much power any plugged-in device is using.Measure Computer Power Supply Unit Wattage with External Power Meter
  • To use one, just plug it into the wall, then plug your computer’s power cable into it. Turn on your computer, and watch the numbers go.
  • This method gives you real-time data on how much electricity your PC is using.
  • Just remember, the number you see will be for everything in your computer, so make sure it’s the only thing plugged into the meter.

Some ending thoughts

When it all comes down to it, checking the label on your power supply is the surest way to know its wattage. While software and estimates can give you a ballpark figure, that label tells you exactly what you need to know, especially if you’re thinking about adding new parts or upgrading.

Knowing how much power your PSU can provide is key, not just for keeping things running smoothly today, but also for planning future upgrades. Imagine wanting to get a new, power-hungry graphics card without knowing if your PSU can handle it. That could lead to trouble like not enough power for all parts or, worse, damaging your precious components.

At the end of the day, your power supply is the heart of your computer’s power system. Making sure it’s up to the task of powering everything you need is not just smart; it’s essential, especially as computers and their components only get more powerful over time.

Nyau Wai Hoe
Nyau Wai Hoe is the Founder and Chief Editor of With a degree in software engineering and over 12 years of experience in the tech support industry, Nyau has established himself as an expert in the field, with a primary focus on the Microsoft Windows operating system. As a tech enthusiast, he loves exploring new technologies and leveraging them to solve real-life problems.

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