Earlier quoted context omitted.
> This is partially because credit card receipts only include the total, not the tax separated out. So really, anything under around 22% is a bad tip. Can you explain the math? Why is this amount higher than 20% rather than lower than 20%?
The credit card receipt shows 1 total: food+tax. So the amount the server is basing the tip off is higher than what I am. So for me to tip what they think is 20%, I have to tip what I think is 22%.
Ah, got it. I tip base off of the pre-tax amount just out of principle.