Here's examine.com on the recommended amounts: https://examine.com/nutrition/how-much-protein-do-you-need/. I'm of fairly healthy weight, active and have been losing some weight, so I should be getting 2.2-3.3 g/kg according to that. I have two protein shakes a day and build every meal around as much protein as possible while still having it resemble normal food, and I'm achieving an average of about 2.2g/kg, i.e. just at the lower end of where I should be. Particularly when trying to lose weight, getting the amount of protein required in the calories allowed is really tough. It's easier when maintaining weight or trying to gain weight since the protein requirements are similar but you have more calories to play with.
I'm 46, so soon I'll be in the 50+ group which the examine.com article says is when you start needing more protein in a single dose. For me that's about 36g per meal - about 6 eggs, for example.
Counting calories is a bit of a pain to get started with, but isn't too bad once you're going since most people tend to repeat meals frequently. But it's been really illuminating - I thought I ate well previously, but I was a long way from where I needed to be. It's pretty geeky but has been really interesting. I've realised that it's essentially impossible to eat the way I should do eating food I don't prepare myself - nothing has anywhere near enough protein. Data driven health FTW.