restaurant tip- before or after tax? (US)?

After tax , you can do it either way but it's not a big enough difference to do it before hand.

This is the US "full service" standard restaurant tipping guide.

Server: 15% - 20% of the total bill before taxes (Note: some restaurants now suggest tipping after taxes because servers themselves tip out on the after tax amount).

Wine Served with Dinner: The safe recommendation is to tip 15-20% of the total bill, including alcohol, even for expensive bottles of wine. However, we've seen some restaurants say it's OK to tip around 10% for expensive wines.

Bartenders: 15% - 20% of the tab; or, $1 for beer or wine, $2 for mixed drinks. Ideally, pay your bar tab before leaving for your table.

To play devil's advocate for the server: The "In America" comment was rude, yes. However, this kind of frustration builds up after years of serving where people from other countries (who may not be savvy to America's tipping policy) don't tip well at all. I worked in LA, where about a third of my tables were from other countries (British, Chinese, Mexican, etc.) and about 80% of the time I would get less than 10% tips from them, when Americans tipped me 20% on average. It makes you grumpy when you get a table of foreign people. It's not being racist, it's just basing it on experience. Second, people have started tipping on the total (including tax) so much that more and more restaurants have their servers "tip out" (give a portion of your tips to the bartenders, bussers, even cooks) based on TOTAL SALES including taxes. A 15% tip is bad enough without it being pre-tax. And about you being college students who can't afford to be generous, well there's a saying that servers have: If you can't afford to tip, you can't afford to eat out. Not to be mean, but I guarantee this is what your server was thinking. He might have had a bad day, too, and your table was the last straw. These things happen. And these other answers saying that 15% is a perfectly good tip, they obviously don't know how the restaurant industry works. For example, "AB"'s answer up there. It's ridiculous. If she has ever gone to the same restaurant twice after tipping the way she's explaining, she's lucky if multiple servers haven't sneezed in her food by now. Not tipping on alcohol drinks??? Of course you're supposed to! Take it from me, an actual server, who can't pay his college tuition if he gets 15% tips all day, and whose service to his tables is worth the 5 to 10 bucks on the average bill.

Since I usually tip in the 20 to 30 percent range, it doesn't really matter since any way you calculate it, I'm still tipping 15% pre or post tax though nowadays servers want 20% to be the norm

Proper tipping is supposedly before tax, not on alcoholic beverages either as that is supposed to be a separate tip.

I tip after taxes but each his own

Your tip is based on the total bill so it is after taxes.

I live in a low tax state (6%) so I always do tax times 3 to get me the tip amount. 18% is about right.

I belive that you tip based on the service not on the amount before or after taxt. I usually tip after tax.

Before tax. You don.t tip tax.

Before tax... The waitress has nothing to do with the states local requirements.