When to add more RAM / Memory

Windows 7, 8.1 and 10 64-bit use about 4 GB of memory in normal use.

Most any user will not run out of memory with 8 GB of memory.

I have 16 GB of memory on my own machine to run Virtual Machines. Most of the time only 4 GB is in use.

Unless you have some memory hungry app (does not look like it), adding memory beyond the 16 GB you have is a waste of money. It will not be used.

Use Performance Monitor. Key values are

Memory - Pages /sec and Avg.
Memory - Disk sec/Transfer

Thanks for the replies. I thought maybe even when I'm down close to 3 Gigs remaining, I should be ok. How low would you folks personally go (e.g. 1-2 Gigs) before you would think of adding or even with that number, would you still consider all to be well?
Again, thank you so much for the warp speed replies!

See what is using all the memory. Task Manager or Resource Manager will tell in addition to the above post.

Unless you are using all memory, you should not need to add.

Key question, however, is what is using all the memory?

I am usually at around 86%

I am rarely over 25% in use. I need Virtual Machines running to increase that usage.

I rarely dont have VMs running

if this is for your own machine, then you are probably fine until you are out of memory. Order some and be done. If this is for a server and it is critical that uptime and performance be preserved, then there is never a wrong time to add memory. Just keep in mind memory limits of machines and operating systems. For example, Windows 7 Home Premium has a limit of 16GB, and it looks like not all ASUS Rogue machines support the same amount of RAM - some 16GB and some 32GB.

Thanks again for the informative replies. The OS is Windows 10 with Creator's Update. The machine is mine own and it has 4 slots all used for 16 Gigs. I can up it to 32 Gigs if I so wish. But from what I'm getting in your responses, I can leave well enough alone unless I see it go down to zero left for Memory. I've got the Virtual Memory set for 16 MB max. But before I would get so low and have to resort to that (virtual memory) I would add another 16 Gigs.
But the main thing I was concerned about was it being down to 3.6 (as it is now showing) and if that was getting too low. Since I understand it is not, I probably will leave well enough alone. It's not going to break the Bank to buy it if I need to so plus I am desperate for the Air Miles!?!
I seriously appreciate the feedback and the advice. If there's more you would see to add, I'm listening. I would be considered less than a novice when it comes to the technical side of computers.

Shaun, I notice you say you have about 86% memory used. How much total RAM do you have aboard if you don't mind saying?

Use the tools mentioned to see what is using all the memory. On hundreds of 64-bit machines over time, 4 GB is lots for most users and 8 GB suffices for 99% of users, so then what is running.

My 25% is 1/4 of 16 GB

Logos Bible Software is the biggest consumer. Another under "commit" called ns.exe (not sure what this is) is showing 662,716. Then Logos is showing a number of a mere 770,704.
Chrome follows with the next biggest numbers, e.g. 156,868 / 135,976 / 107,972 / 138,052 / 169,204 which as you know fluctuate a bit.

Quit Logos , wait a minute, check overall memory, restart Logos and measure again. If using more than (say) 500MB ask the software manufacturer.

Chrome and IE use memory for each tab. I only keep 3 or 4 tabs active at one time

Rebooted the Laptop. Brought up Outlook 2013 / Chrome with three tabs opened but when I go to Task Manager, I see Chrome mentioned 8 times with the third one showing a number of 106 - 107.
When I open Logos, it starts under Memory showing 240 MB then after several minutes not opening anything it goes to 321 MB. This program is massive and we know from experience this is a memory hog big time.
With Outlook 2013 / Chrome / Logos / Online Bible and not using anything, right now I'm showing in Task Manager 7.5 GB available. I've not seen it go down below 3 GB but I've not been watching that much until lately. Don't ask me why I even bothered to look at it at all ... I just did and noticed the numbers between 3-4 Gigs available. Thus my question at the beginning.
If you were in my swivel chair before this Laptop and happened to notice, let's say 1 GB available, would you add more RAM or leave it as pointed out earlier, wait till there was no RAM available?

Very good. Thank you so much for the expertise! Appreciated muchly!!!

Appreciate this forum. Replies have come in on warp drive which beats sitting around for days waiting for a reply to come rumbling down the pipes. Thank you again to all those who contributed!!!

You are very welcome and I was happy to help.