So, basically, HF20 now has a means for dealing with all the resources needed for transactions. Now, every account has a certain amount of RC's. Everyone has a different amount. More SP means earning more RC's. Every transaction uses, or costs a certain amount of RC's.
Here's the challenge... it's NOT like a resteem uses 1 RC, and a comment uses 4 RC, and a post uses 10.
It's relative. Relative meaning, a comment uses RC's based on how big a comment it is. A few sentences is more than 3 words. AND a few paragraphs is more than a few sentences. etc.
Long posts are more than short posts. All of that makes sense. It takes more to make a transaction of 15,000 characters vs 1000 characters. It takes more network time, more server time, etc.
A decent rule of thumb, after some experimenting with this Account of 15 SP, is, about 5-10 comments a day. 1 small comment of a few words is about 3%, two-three sentences is 4% RC and a paragraph for comment is 4.5-5% of RC in a day.
A post takes about 4% to 8% of RC's depending on the amount of RC's you start with!
Oh, and as if all this isn't challenging enough to figure it out... all of this also depends on NEWTORK and BLOCKCHAIN activity also. Meaning if you make a transaction, WHEN it is busy, it costs more RC than if you make a transaction when activity is Slow!!!
Or, ...the slow and steady, commenting and building it all up slowly!
BTW, this post actually uses 4% of my own Resource Credits...
I hope all this helps!