The Basic Formula
Calculating a tip is straightforward once you know the formula. The tip amount equals your bill multiplied by the tip percentage, expressed as a decimal:
For example, on an $80 dinner bill with a 20% tip: $80 × 0.20 = $16 tip. The total you'd pay is $80 + $16 = $96. If you're splitting with a friend, each person pays $48.
Quick Mental Math Tricks
You don't always have your phone handy. These shortcuts let you calculate a tip in your head in seconds:
- 10% tip: Move the decimal one place left. On a $64 bill, 10% = $6.40.
- 15% tip: Find 10%, then add half. $6.40 + $3.20 = $9.60.
- 20% tip: Find 10% and double it. $6.40 × 2 = $12.80.
- 25% tip: Divide by 4. $64 ÷ 4 = $16.00.
The 20% trick is the most useful to memorize because 20% has become the standard tip at sit-down restaurants in the United States. If your bill ends in a round number, you can calculate 20% instantly.
Tipping Etiquette by Situation
Tipping norms vary significantly depending on the type of service. Here's a breakdown of widely accepted standards in the United States:
Sit-Down Restaurants
This is the most common tipping scenario. The general standard is 15–20% of the pre-tax bill for acceptable service, and 20–25% for very good or exceptional service. Tipping below 15% is generally considered a signal of poor service.
A common point of confusion: should you tip on the pre-tax total or the full amount including tax? Technically, tipping on the pre-tax subtotal is correct, since your server didn't provide the tax. However, on a typical restaurant bill, the difference is only $1–$2, and many people tip on the total for simplicity.
Food Delivery
Delivery tipping has become more important as platforms like DoorDash and Uber Eats route orders to independent contractors who depend on tips. A reasonable delivery tip is $3–$5 minimum, or 15–20% of the order value — whichever is higher. For orders over $50, percentage-based tipping (15–20%) is more appropriate.
Factors that justify tipping higher: long delivery distance, bad weather, large and heavy orders, or a particularly fast delivery time.
Takeout / Counter Service
Tipping at takeout counters is optional. If someone took the time to pack your order carefully and get everything right, a 10% tip is a nice acknowledgment. At coffee shops and similar counter-service spots, $1–$2 per drink is common if service went above and beyond. You're not obligated to tip for simple counter transactions.
Hotel Services
Hotel tipping follows different conventions: $2–$5 per bag for bellhops, $2–$5 per night left for housekeeping (left daily, not just at checkout), and $1–$2 for valet parking when your car is returned. Room service tips are typically 15–20% of the bill, though some hotels already include a service charge.
Personal Care Services
For haircuts, salon services, and personal care, the standard is 15–20% of the service price. If the stylist or technician is also the owner, tipping is still appropriate (the old rule that you don't tip owners has largely disappeared). For spa services, 18–20% is typical.
Automatic Gratuity: What to Watch For
Many restaurants add an automatic gratuity (auto-grat) for parties of 6 or more, typically 18–20%. This will appear on your bill as "gratuity," "service charge," or "auto-grat." If you see this charge, you've already tipped — adding more is entirely optional and only warranted if service was exceptional.
Always scan your bill before calculating a tip. Missing an auto-grat and adding a second tip on top of it is one of the most common and costly restaurant mistakes.
Splitting the Bill
When splitting evenly, add the tip to the total first, then divide. Do not split the pre-tip bill and have each person tip individually — this leads to underpaying the server due to rounding.
Example: $120 bill, 20% tip = $24 tip, $144 total. Split 4 ways: $36 per person.
For uneven splits (people ordered different amounts), you have two options: (1) itemize each person's portion and apply the tip percentage to their subtotal, or (2) calculate the total tip as a group and allocate it proportionally by what each person spent.
Tipping in Other Countries
Tipping culture varies dramatically around the world. In Japan, tipping is considered rude — service is seen as a professional duty, not something to reward with extra cash. In most of Europe, rounding up or leaving 5–10% is common but not mandatory. In Australia and New Zealand, tipping is appreciated but optional.
Before traveling internationally, it's worth researching the local tipping customs. Tipping in a country where it's not expected can sometimes cause confusion or offense.