NumberTally How the Tip Math Works
Tipping is simple percentage arithmetic, applied in order. The tip is figured on the pre-tax bill — tax is not part of the service you received — then tax is added, and the grand total is split evenly:
Tip = Bill × Tip%
Tax = Bill × Tax% · Total = Bill + Tax + Tip
Each person pays = Total ÷ People
Shortcut for 20%: move the decimal one place left (that’s 10%) and double it. A 20% tip on a $50 bill is $5 doubled, or $10.
Tipping Guide by Situation
In the United States, 15–20% of the pre-tax bill is standard for full-service restaurants: 15% for adequate service, 20% or more for great service. Bars run about $1–2 per drink or 15–20% of the tab; delivery drivers 10–15% since they cover their own vehicle and time; takeout is optional, though 5–10% is appreciated. For poor service, many people tip around 10% and speak with a manager — a low tip alone rarely communicates what went wrong.
Frequently Asked Questions
What percentage should I tip at a restaurant?
In the United States, 15–20% of the pre-tax bill is the standard tip for full-service restaurants. 15% is typical for adequate service, 20% (or more) for great service.
Do I tip on the bill before or after tax?
Tip on the pre-tax subtotal. Tax is not part of the service you received, so the standard practice is to calculate the tip percentage on the bill before sales tax is added.
How do I split the bill evenly between people?
Add the tip (and tax) to the bill to get the total, then divide by the number of people. For example, a $101.40 total split among 4 people is $25.35 per person.
What should I do if the service was bad?
Tipping is customary but not legally required. For poor service, many people tip around 10% and speak with a manager about the problem, since a low tip alone may not communicate what went wrong.
Should I tip on takeout or delivery orders?
For delivery, 10–15% (or more) is customary since the driver uses their own vehicle and time. For takeout, tipping is optional — a small amount such as 5–10% is appreciated but not expected.