How much memory do I need?

Thanks to the conversation about upgrading my 2014 iMac in this thread I have decided to go the route of Mac mini or Macbook (either Air or Pro) with an external display. I'm a bit overwhelmed by options and trying to figure out how much unified memory I need for my new machine.

I currently have 32GB RAM. I typically don't have issues with performance, unless I'm rendering a bunch of high res previews in Lightroom while trying to edit video (something I rarely do) or do something else that is very memory hungry. My biggest memory needs are for Lightroom and Photoshop, otherwise I do few memory intensive tasks.

I have been Apple's Activity Monitor the past couple days to see how much of that I routinely use.

Physical Memory 32 GB
Memory Used ranges from 20-25 GB - of this about 14-16GB is App memory, 3.7-3.9 GB is Wired Memory, and Compressed ranges from 2.81-6.31 GB
Cached Files 5-6 GB
Swap Used 5-6 GB

Lightroom uses 11-16 GB, Photoshop about 2.8-2.9 GB of memory.

I honestly don't understand what most of that means and don't have a sense of if cached and swap memory are high because my computer is a decade old. I suspect I need at least 32GB on a new machine based on that usage, but don't have a sense of whether or not I could get away with 24GB because the new processors will run more efficiently, or if I should get more than 32GB based on anticipating that my memory needs will grow with new OS and software updates. I'm not opposed to buying used/refurbished and hope whatever machine I get I can use for at least another 5 years. Budget is tight (especially with needing to buy a display and peripherals for a new machine), so trying to invest wisely in necessary upgrades but not overspend on something I don't need. TIA for any advice you can offer!

I use an M1 Max 14" MacBook Pro with 64GB of memory.  My suggestion for you would be at least 32GB, and preferably more if you can afford it.  Memory is your best investment as an "upgrade" before SSD or processor.  

I went with a Mac mini M4 Pro recently with 64gb RAM. I'm not computer guru, (a million miles from that, lol), but RAM is nice... 32gb ought to do it but seems better to add at outset for future needs. Ditto Mark's thoughts.

I'm not an expert, but based on my experience, 32 would be the minimum.

Macs normally use as much RAM as available. On computers with 32GB, you might see some swap, with 64GB less so unless you do some very RAM-heavy tasks. If you do the occasional video editing, 64GB might be preferable if it is in the budget.

Hi
My policy and two bits worth go for the max you can afford. Simple

In today's environment with big files, lots of memory use by programs and apps, huge chunks of memory being allocated by the OS to itself, multiple things running simultaneous, I would consider 32GB to be a bare minimum, 64GB to be decent and 128 being the best price/performance compromise. Anything above that is gravy!