I'm calculating my percentage on post tax bills...because that's how people tip. You take the total, then tip 20%. Then I'm happy, you're happy, everyone's happy.
It's 1:30 in the morning here, so I'm gonna post my findings tomorrow. I didn't have the greatest shift. My sales weren't as high as they could have been because I had some campers, and I got some parties of 2 or 3 on my tables that fit 6 easily. I normally sell between 1300-1600 on a saturday night. Tonight I only sold 1000. All things considered I still walked with 15%. That's after I tipped out the bartender, bussers, hosts, food runners, and drink runner the required total of 4.25%. So I averaged about 19 percent on my sales.
I'll post my findings tomorrow. As a fun little extra, I noted the age, gender, and race of every person that paid the check and left the tip. I figured NT would have fun with that, they always do.