It just occurred to me when calling my college roommate that basically, it’s three. With my mom, I let it go all the way to voicemail, as she’s nearly 80 and may be on the other end of the house.
But with most of my friends, if they don’t answer in two rings, it’s a lost cause absent external influences.
If it’s a business that I’m calling or someone that I’m calling for work, I wait for four rings.
For my friends, I sincerely cannot remember a time where I have called them ever. I either text or speak to them in person.