How to Check Power Supply Wattage without Opening?

As a computer geek, you know that Wattage is one of the major factors determining a component’s effectiveness. When the Wattage is too low, the part will not work in most cases. So the first thing to do is to check the power supply’s Wattage, but how to check the power supply wattage without opening? Checking the power supply wattage is a simple process. 

You can check it from the outside of your computer’s case. It is a good troubleshooting step to see if the power supply is putting out the proper Wattage. A mysterious digital logic power supply engineer at Foshan city in Guangdong province provides some tricks.

What Is Wattage?

How to Check Power Supply Wattage without Opening

Wattage measures the maximum quantity of electrical electricity a tool can use. The higher the Wattage, the more energy it uses. In the right circumstances, high Wattage can be a good thing. For example, a 1000 watt microwave has more output than a 600-watt microwave, which will heat food faster.

If you have the space, a larger device is always better. However, Wattage can also be bad. If you have a large device and are limited on space, such a high-wattage device will have to be plugged into a power bar. 

It can turn your nice, clean power strip into a mess of wires. Wattage is not an indicator of how well a device works, nor is it an indicator of how much it will heat your food. Rather, Wattage is an indicator of how much power a device can use. The amount of power used by a device depends upon the device’s design and how much power the device needs to operate.

Why do you need To Know Wattage?

How to Check Power Supply Wattage without Opening

Knowing your Wattage will help you to choose the right antenna. The higher the Wattage, the better the antenna will be. Also, you may ask your local radio amateur(s) to help you in this regard. You can also check out some local ham radio clubs. Finally, you can buy an antenna analyzer that will tell you the Wattage of a particular antenna and tell you the impedance of the antenna.

What Is A Wattage Rating?

What Is A Wattage Rating

The wattage score refers to how good a deal of electricity it uses. The better the Wattage, the brighter the mild will be. It also means that the bulb will be hotter and use more energy—# watts x Volts = watts of power. So, a 100w bulb would have 12v.

Why Do You Need To Check Power Supply Wattage?

Why Do You Need To Check Power Supply Wattage

You will require checking the power supply wattage to ensure you have the right connections for your computer system. In recent times, it’s far essential to ensure your power delivery is enough in your laptop hardware. You would not need to be in a situation wherein you cannot do any paintings because your device doesn’t have sufficient electricity to function. 

If you have bought a decent power supply unit for your high-end gaming rig, you must check the Wattage once in a while. A high-end gaming rig has many devices inside, which all need to use power, and that requires a good power supply. While some power supply units can provide you with wattage of over 1,000 watts, a good gaming power supply unit should be able to provide you with a minimum of 1,500 watts. 

How To Check Power Supply Wattage Without Establishing It?

How To Check Power Supply Wattage Without Establishing It

The subsequent techniques may use to decide power delivery Wattage without starting the case:

  • Check the power supply label or sticker on the side of your power supply. Some manufacturers will print the wattage rating right on the label. 
  • If you are old-fashioned, you can check the rating of the power supply by putting a voltmeter across the two prongs that plug into the wall outlet. 
  • When you have more modern electricity delivery, you may use an electricity delivery load tester to determine the amperage that the energy delivery attracts. Click here to download Power Supply Load Tester.

Can I Check The Power Supply Wattage Online?

Can I Check The Power Supply Wattage Online

Because the power supply is such a crucial component of any gadget, it’s important to double-check its Wattage before purchasing or using it. Suppose you are purchasing a new computer or any other electronic device.

There are many ways to limit the power supply wattage online, and they are all simple. One easy way is to Google the model number of the device you are looking for and then click on Power Supply. 

Then on the subsequent web page, it’ll list the Wattage in conjunction with the price of the electricity delivered. If you cannot find the model number or Wattage on the power supply, you can also look up the device’s manual. The manual will mention the power requirement for the device, and you can use that information to find the Wattage. 

For finding the model number of the device, you can use the serial number to find the model number. But the serial number is usually printed on the sticker, and sometimes, even under the device, you need to look carefully.

How to Check the Actual Power Supply Wattage of Your Laptop?

How to Check the Actual Power Supply Wattage of Your Laptop

There are two ways to check the Wattage of your laptop. The first way is to check the laptop’s label, typically found on the laptop’s bottom. Some laptop manufacturers place other stickers with the name, model, and serial number, but if you can’t find the label, there is another way to check the Wattage. 

Most laptops have a very large power brick that contains the power supply and the power cord that connects to the computer. The power brick will list the Wattage on the chassis of the brick. It is a good way to check the Wattage if you only have the power brick and no laptop.

What Are The Damages If You Use A 160-Watt Power Supply With A 300-Watt Laptop?

What Are The Damages If You Use A 160-Watt Power Supply With A 300-Watt Laptop

The generic and easy solution to this question is that if you continuously use the power supply with a machine that requires more Wattage than the power supply can provide, the machine will eventually overheat and shut down.

The more technical answer will be if the power supply’s Wattage is insufficient to keep the machine running under load for a long time. It will eventually overheat and shut down because the power supply will not keep up with the machine’s power to run at full load.

How to Measure the Wattage and Voltages on A PSU?

How to Measure the Wattage and Voltages on A PSU

To measure the Wattage of a PSU, you need to calculate the VA. VA of a unit is the product of the Wattage and the voltage. 

There are two methods to calculate the VA of a unit: 

  • Multiply the present voltage squared by the present current 
  • Multiply the present voltage by the present current. To measure voltage, you need to know the pin configuration of the unit. The sharper the light, the higher the Wattage. Once you have the VA of the PSU, multiply it by 1000 to get the Wattage. For example, if the unit’s voltage is 12V and the current is 6A, the VA is 12V*6A*1000=7200W.

How to Check Power Supply Wattage on Watt Meter?

How to Check Power Supply Wattage on Watt Meter

Initially, you need to buy a wattmeter. These are available inside the marketplace for as reasonably priced as 20-25$. So, it won’t be a great loss even if you buy one for your personal use. It will come with a cable and a display unit.

All you need to do is connect the power supply to the display unit and start measuring the watts. Most of the power supplies will have a sticker to tell you the watts. But if it doesn’t, you can easily find it by looking for the power cable or the power input slot. The voltage and amps can also find on the power supply’s sticker.

Frequently Asked Questions

How Do You Check Your Power Supply Wattage Without Opening The Computer Case?

  • The sticker on the side of the power supply
  • The sticker on the side of the computer case

How Do I Check My Power Supply Voltage?

  • Look at the sticker on the supply itself
  • Use a voltmeter and check each cable on the supply

How Do I Discover The Wattage Of My Power Supply?

  • Go to Control Panel > Hardware and Sound Option > Power Options > Edit Plan Settings.
  • Go to Control Panel > System and Security > Device Manager > System Devices

How Do I Check My Power Supply Wattage In BIOS?

  • Check the sticker on the side of the PSU. 
  • Hack into BIOS settings using a keyboard. 


This blog will teach you to check power supply wattage without opening it. Modern power supplies are surprisingly capable of generating a wide range of voltages, even when the nominal voltage is a low value like 5V. Many power supplies can safely use with voltages outside their short scope. However, suppose you’re using a power supply never intended to generate voltages outside its intended range. In that case, you’ll need to take precautions to avoid damage to the supply, your load, and possibly you.

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