Tipping math shouldn’t slow down the end of a good meal. This guide covers the standard percentages, how to split a tip across a group, and how to handle tax and rounding.
The standard percentages
In the United States, 15–20% of the pre-tax bill is standard for sit-down service, with 20% for great service and 15% for adequate. For takeout, 10% or rounding up is appreciated but optional.
The quick mental method
To find 20%, move the decimal one place left and double it: a $46 bill → $4.60 → ×2 = $9.20. For 15%, take half of 20% and add half of 10%: $9.20 ÷ 2 = $4.60, plus $2.30 = $6.90.
Splitting the bill
Add the tip to the bill to get the total, then divide by the number of people. A $86.40 bill with an 18% tip ($15.55) totals $101.95; split between two, that’s $50.98 each.
Should you tip on tax?
Convention says tip on the pre-tax subtotal. The difference is small, but it’s the standard base. Some people round up to include tax for simplicity — either is acceptable.
When a gratuity is already included
Large groups often have an automatic 18% gratuity added. Check the receipt before adding more — double-tipping is generous but unnecessary, and the included amount is usually enough.