As Archie Bunker would say, “Oh, geez Louise”.

$0 is a round number.

In the US I start out at 15%, on the pretax cost of food. Service bad, it goes down. Really bad, I talk to the manager. Service good, it goes up. 20% is the top end usually, unless they’ve done something special.

I do prefer it in much of Asia, where there is no expectation of a tip, or a moderate 5-10% service charge added to the bill. As many past tipping threads have pointed out, in the US, there is a steady and gradual creeping up of what is acceptable. Not even going to get into the silly tip the bill stuff.