Best PC Power Supply Calculators

Building a new PC is full of challenges, but getting an appropriate PSU (power supply unit) is often overlooked.

The reason for this is that the PSUs aren’t expensive and there is plenty of variety so people approach this subject with an air of nonchalance where they believe that getting a 500-600W unit will be enough and they move on.

The issue here is much deeper than that and getting the proper PSU should be looked in the same way as getting the right GPU or CPU for your computer. Just like with those, there are tiers that relate to both price points, but more importantly quality and capability.

In the old days (well, maybe ten or fifteen years ago), it was up to the would-be PC builder to manually calculate how much power their new gaming rig is going to need. You would have to sum up the usage of the graphics card and the processor and RAM and fans… It was a tedious job.

Luckily, some really smart people came up with a cool solution – a power supply calculator. At this point in time, we can simply enter the models of each component we plan to have inside our computer and we get an exact figure of how much is our power requirement.

PC Components
Your PC components need power. Image credit: CNET

Some have gone even a step further and added a suggestion for the exact model that will fit your build. Although this trick was taken advantage of by certain PSU manufactures who naturally suggest only their models, there are still some good power supply calculators by those companies out there so they will be included in this list.

There are a few more key things to factor in that these calculators might not always be precise for, but then again, it’s not their job to do this.

We’re talking about stuff like physical dimensions of a PSU. When building a PC, you should be aware that the PSU will probably take the biggest part of your rig, so you need to take space into consideration as well. Of course, PC case makers were aware of this, so most modern cases have a dedicated PSU space.

However, the room for the PSU is only one part of the equation. You have to be aware that the PSU does generate a lot of heat and with other hot components inside the case, the airflow is an important thing to consider.

Another thing to keep in mind is the types of power connectors. Some RTX 3000 series rumors suggest that there will be a new power cable required, a 12-pin one.

Those are just some of the things worth paying attention to when getting a PSU, but that doesn’t mean that power supply calculators are not worthy. The fact of the matter is that they are still a really good solution for this issue and should definitely be used when building a new PC or upgrading your old one.

Related:What Power Supply Do I Have?

Let’s see what are some of the best power calculators out there.

Table of ContentsShow



What’s interesting about OuterVision is that this is a website dedicated to only and exclusively calculating the power consumption and as such it’s bound to yield the best results. The great thing about this calculator is that it will automatically find the best PSU and the link to buy it on Amazon.

This website has an almost perfect interface. It’s very easy to use, offers a wide variety of options, and there are two separate PCU calculators, one made for experts and the other for beginners.

Another cool thing about this calculator is that it offers overclocking calculations as well. So if you know from the start that you’re going to overclock your components, this is a perfect tool for you.


PC Part Picker

Although the name doesn’t sound like it, and especially if you have any experience with this website, PCPartPicker is actually a really good power calculating website. Of course, as the name suggests, they mainly deal with choosing the new parts for your PC and can be a great tool when building it for the first time.

Seeing how they’re not purely a power calculator, they offer plenty of other advantages such as checking for compatibility between the different parts of your computer which is really handy when building a PC.

However, their process is a bit backward for picking the best PSU seeing how you first choose a PSU and then they tell you if it’s compatible or not. This means that you will actually go into the process a little blindly if you don’t already have knowledge and experience in the PC building.



This is an extremely well-known name among computer enthusiasts. Many have heard of it because it offers great deals on PC components (among other things) and because it has an excellent PC building tool embedded in it.

Although this PC building component picking solution isn’t as good as, say,, it is still probably among the top 3 best solutions online.

The issue with their PSU calculator is that it’s relatively rudimentary and doesn’t account for stuff like fans and peripherals. Admittedly, they aren’t huge power consumers, but it would still be nice to have them taken into consideration.

Newegg only shows the recommended wattage, which is a good thing, but the problem with the suggested PSUs that are offered when you calculate the necessary power consumption.

For example, if their calculator came up with a number of 595 Watts required and you click on the ‘Show PSUs’ button, you will be taken to their search page with PSU parameters already inputted.

However, those parameters will be ‘500-599W’ meaning that you will be offered a 500W power supply when the recommended power requirement is 595W.


PC-Builds is a really unique website in that it doesn’t offer to build a whole PC from parts you choose (pretty ironic, given its name), but it’s not just a PSU calculator either.

They offer stuff like a bottleneck calculator or a ‘Can You Run It’ calculator which determines if your PC can handle a game you want to play.

The calculator interface itself isn’t as straight-forward as the one from OuterVision, but it’s still pretty good compared to others. The great thing about it is that you get a full pie chart breakdown of which component is using exactly what amount of power.

However, they only calculate how power you will need and do not recommend a specific PSU model.



If your first thought is that this a PSU brand, you’re right. But, they do offer a pretty nifty tool on their website to help you calculate exactly how much power your PC is going to need.

In fact, their power calculating tool is probably on par with the best power calculators out there, but then there is this huge downside that it offers only Seasonic PSUs. Of course, depending on how you look at it, this may not be so bad as Seasonic is a pretty good PSU manufacturer, but as PC building enthusiasts, we like to have as many options as possible.

Be quiet!

be quiet!

This is another brand-based calculator that will offer you a pretty basic approach. This isn’t a bad thing as you can pretty much calculate all your power needs, but it would still be better if you had the option of adding additional power consumers.

As a calculator from a certain brand, you will naturally get only recommendations for a PSU from that brand, but seeing how ‘be quiet!’ is a pretty good PSU making company, you shouldn’t be too concerned.

Cooler Master

Cooler Master

Power supply calculators from brands aren’t necessarily a bad thing. In fact, the solution offered by Cooler Master is definitely as good as some non-brand specific calculators, and maybe even better than some.

The options are pretty basic, but they offer a really cool feature that allows you to customize what PSU you want after the recommendation is made by choosing what type of cable management you have in mind and what sort of efficiency rating are you looking for.

You Might Like These Too

Aleksandar Cosic
Aleksandar Cosic

Alex is a Computer Science student and a former game designer. That has enabled him to develop skills in critical thinking and fair analysis. As a CS student, Aleksandar has very in-depth technical knowledge about computers, and he also likes to stay current with new technologies.