Right click on the pdf thumbnail and scroll to "properties" Under "general" in your pdf viewer it should have a size.I don't know, All I know is I am told I need to be under 4 MB and most of my brochures are below that and work just some are just over I am told
So based on what I have been told I would say between 4 MB and 5 MB but I need it under 4 MB
I just need them for quick emails through CRM when I do quotes anything larger I can go directly through my own email its fine
The brochures are all company ( near a dozen companies) med Supp brochures fro various states
An alternative to resizing software is to just go to fiverr and pay someone a few bucks to do a redesign with your file size specifications. It may end up looking better than trying to do it yourself because you can request edits and focus on the graphics/fonts etc. that you deem important.