How to Calculate a Tip
Tipping conventions vary by country, industry, and service type. In the United States, tipping is expected at sit-down restaurants, bars, hair salons, taxis, and hotel housekeeping. Understanding how to calculate a tip quickly and accurately prevents both under-tipping — which is unfair to service workers — and over-tipping, which strains budgets unnecessarily.
The Formula
Per Person = (Bill + Tip) ÷ People
Standard Tipping Rates by Context
Restaurants (Sit-Down)
15% for standard service, 18–20% for good service, 20–25% for exceptional service. The 18% preset is the current US average. In the UK, 10–15% is typical and not always expected at casual dining.
Food Delivery & Bars
Food delivery: 15–20% of the order total with a $3–5 minimum regardless of order size. Bars: $1–2 per drink for simple orders, 15–20% for tab service or complex cocktails.
Pre-Tax vs Post-Tax Tipping
Tipping on the pre-tax amount is technically more correct — the server did not provide the sales tax as a service. However, on a $100 meal with 8% tax, the difference between tipping 20% on $100 versus $108 is $1.60. Most people tip on the post-tax total shown at the bottom of the bill for simplicity, and both are socially acceptable.