Building A PC? This Online PSU Wattage Calculator Will Help.

Building your own PC, rather than buying one off the shelf, can be very rewarding.  And it can save you money too.  But there are lots of important things you need to consider, such as making sure that the CPU, motherboard and RAM are all going to fit together.

But before all that, you need to buy a case and a power supply.  And it can be difficult to know how big a PSU you're going to need.

So here's a great way of finding out.  Just use the free PSU Calculator at  Tell it the type of CPU you're using, and how much RAM, and what sort of processor, etc etc, and it'll give you a pretty good estimate of the number of watts your PSU needs to be capable of putting out.  It'll also link you to some suitable power supplies that the site happens to sell, of course, but you can always shop elsewhere if you'd rather.

This is a pretty specialised area, but such an online tool is definitely handy.  Whether you're planning to build a new machine from scratch, or whether you're planning a big hardware upgrade and you need to know whether the existing PSU will be up to the job.



My thanks to reader "Gator" for this hot find.


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by B-O (not verified) on 22. November 2010 - 8:17  (61483)

Seems ok, but I much prefer this one:

Accurate, detailed and still simple to use!

by morrig on 23. November 2010 - 17:49  (61570)

With your suggested it gave 273 watts for my system,i5-760,4gig,but this one gave 395 seems more correct.

Recently built this and guessed at 450 watts? so about right.

by Gator on 22. November 2010 - 6:46  (61479)

@r.schifreen - Cheers! Glad you found this one useful!
(Yer rightin skils are lots more gooder than minez.) :D

by 26Dolphins on 21. November 2010 - 21:43  (61469)

Thanks, bookmarked for future use.

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