When beginners are building their first PC, they often get confused about which power supply (PSU) will fit into which type of PC case.
After building several PCs over the past couple of years, I’m here to explain the various types of power supplies (PSU) and PC cases and help you understand which PSU types will fit inside different PC cases.
There are various types of power supplies (PSUs) with different physical sizes, and not all of these PSUs will fit into various PC case sizes.
Before we get into which PSU types fit in which PC case sizes, let’s take a look at the different PSU and PC case sizes. So, keep reading this article to find answers to all your questions.
Types Of PSUs & PC Cases (Based on Sizes)
There are many different types of power supplies (PSUs), such as ATX, SFX, TFX, and Flex ATX. There are also different sizes of PC cases, such as full towers, mid-towers, mini towers, and mini ITX cases. Let’s take a closer look at these different PSUs and case sizes.
Different PSU Sizes
There are various types of PSU sizes like ATX, SFX, TFX, LFX, and their measurements are listed below-
| PSU Standard | Sizes (Width, Height, Depth) |
| ATX PS/2 | 150mm(W) x 86mm(H) x 140mm (D) |
| ATX PS/3 | 150mm(W) x 86mm(H) x 100mm (D) |
| ATX Large | 150mm(W) x 86mm(H) x 180mm (D) |
| ATX- EPS | 150mm(W) x 86mm(H) x 230mm (D) |
| SFX | 125mm(W) x 63.5mm(H) x 100mm (D) |
| TFX | 85mm(W) x 64mm(H) x 175mm (D) |
| LFX | 62mm(W) x 72mm(H) x 210mm (D |
As you can see in the table above, there are four types of ATX power supplies. Among these, the ATX PS/2 is the most common and widely used power supply size, often referred to as the standard power supply size.
However, in the market, two or three types of power supplies are very popular, and these are ATX, SFX, and TFX power supplies. You can learn more about different PSU sizes.
Different PC Case Sizes
There are various kinds of PC cases like Full-Tower, Mid-Tower, Mini-Tower, Micro-ATX, Mini-ITX, and their sizes are shown below.
| Case Type | Dimensions (Sizes) (H x W x D) |
| Full Tower | 559 mm x 229 mm x 559 mm |
| Mid Tower | 457 mm x 190 mm x 457 mm |
| Mini Tower | 305-457 mm x 152-229 mm x 305-457 mm |
| SFF (Small Form Factor) | 305-381 mm x 152-178 mm x 305-381 mm |
The measurements in the table above are estimates, and sometimes the dimensions of PC cases can vary.
Each type of PC Case has a specific space for the different types of PSUs, and therefore it is important to select both these parts carefully.
PSU Size Compatibility With Different PC Cases
As we know, there are various PC case and PSU sizes, and here, I’ve explained which PC case types can work with which power supply types.
| PC Case Types | Compatible PSU Types |
| Full Tower | ATX |
| Mid Tower | ATX |
| Mini Tower | ATX, SFX |
| SFF (Small Form Factor) | SFX, TFX, Flex ATX |
The table above shows that ATX PSUs work with various PC case types, such as Full Tower, Mid Tower, and Mini Tower PC cases.
On the flip side, SFX Power Supplies work well with Mini Tower and Small form factor PC cases. On the other hand, TFX and Flex ATX Power Supplies are only suitable for the Small Form Factor PC cases.
How To Know If PSU Will Fit In PC Case? (Before Buying)
It can be challenging for first-time builders to find a PSU and PC case that work together. That’s why you need to follow some instructions that most PC builders recommend.
Most PC builders say you should buy the case last after you’ve picked the motherboard and power supply. That’s because the motherboard and power supply are the most important parts of the computer, and you need to make sure they are compatible with the other PC components.
For ATX power supplies, you can use Full Tower, Mid Tower, and Mini Tower PC cases. If you have an SFX power supply, you can use Mini Tower and Small Form Factor (SFF) PC cases. But if you have a TFX power supply, you should use SFF PC cases.
If you’re still unsure about which power supply will fit in your chosen PC case, you can visit the PCPartPicker website for help.
Use PCPartPicker Website
PCPartPicker is a great website for beginners to build a PC. You can check the compatibility of all the parts on their website.
Once you go to pcpartspicker.com, click on “Builder,” pick your PSU and PC case, and it will show if they work together or not.
PSU Won’t Fit Inside The Case: What To Do?
If you buy a PSU and a PC case and you find that the PSU doesn’t fit in the case, here are a few things you can do.
- Check The Orientation of the PSU: The power supply unit (PSU) will not fit in the case if it is not oriented correctly. So, you need to check the orientation of the PSU before installing it.
- Remove the Hard Drive Cage: If the hard drive cage or other components are blocking the PSU, you may need to remove them to fit the PSU inside the PC case.
- Mod The PC Case: You can modify the PC case to fit the PSU by cutting some metal or plastic. But if you’re not experienced with case modifications, it’s best not to try it.
- Consider A smaller PSU: If your case is too small for your current PSU, you may need to get a smaller one. There are a variety of smaller PSU form factors available, such as SFX and TFX.
- Replace The PC Case: If your computer case can’t fit your power supply, you might have to think about getting a different case that works with your power supply.
Wrapping Up
This entire article explains that, for ATX power supplies, you can use Full Tower, Mid Tower, and Mini Tower PC cases. If you have an SFX power supply, you can use Mini Tower and Small Form Factor (SFF) PC cases. But if you have a TFX power supply, you should use SFF PC cases.
If you’re not sure which power supply fits in your computer case, you can go to the PCPartsPicker website to see which PSUs & PC cases are compatible.
