How to split the restaurant bill when you didn't order any alcoholic drinks - but all your friends did

When you're out to dinner with friends, the general rule is that everyone will split the check evenly - even if your salad clocked in a few bucks cheaper than your friend's burger.

But if your friends are knocking back round after round of beer while you're sticking to water, it can be frustrating to end up subsidizing their fun when the bill arrives and everyone wants to split it evenly.

If you're abstaining from alcohol - no matter the reason - don't feel obligated to pay the same amount as those who chose to drink.

"The best thing to do would be to take cash," Patricia Napier-Fitzpatrick, founder and president of The Etiquette School of New York, told Business Insider. "Take cash and say, 'Here's for my meal,' and then split the tip evenly with everyone."

Your server had to do the same amount of work regardless, so it's fair to pitch in an equal amount for the tip, but if you're not drinking, you aren't expected to contribute as much as those who had three cocktails.

However, this isn't the time to be meticulous. As with any group meal, you might end up paying a couple bucks more than your exact order, and that's okay.

"Say, 'Here's $20 for I ordered,' and whatever else for the tip - but don't take calculator out," Napier-Fitzpatrick says.