The Quick Answer
To calculate a tip, multiply the bill by the tip percentage as a decimal:
Tip = Bill × (Tip % ÷ 100)
A 20% tip on a $50 bill: $50 × 0.20 = $10.00 tip. Total: $60.00.
For fast mental math: find 10% by moving the decimal left one place, then adjust from there.
The Tip Formula
The formula works for any bill amount and any tip percentage:
Tip Amount = Bill × Tip Rate
Where the tip rate is the percentage expressed as a decimal (15% = 0.15, 18% = 0.18, 20% = 0.20).
Total bill = Bill + Tip
Per person (if splitting) = Total ÷ Number of people
Worked Example
Bill: $85.00, tip: 18%, split between 3 people.
- Tip: $85.00 × 0.18 = $15.30
- Total: $85.00 + $15.30 = $100.30
- Per person: $100.30 ÷ 3 = $33.43
Mental Math Shortcuts
You rarely need a calculator. These tricks work on any bill:
10% — The Starting Point
Move the decimal point one place to the left. That's it.
- $45.00 → $4.50
- $78.20 → $7.82
- $123.50 → $12.35
Every other percentage builds from 10%.
20% — Double the 10%
Find 10%, then multiply by 2.
- $45.00 → $4.50 × 2 = $9.00
- $78.20 → $7.82 × 2 = $15.64
15% — 10% Plus Half
Find 10%, then add half of that amount.
- $45.00 → $4.50 + $2.25 = $6.75
- $78.20 → $7.82 + $3.91 = $11.73
18% — Almost 20%
Find 20% and subtract a small amount. Or find 10% + 10% × 0.8.
- $45.00 → 20% is $9.00, so 18% is roughly $8.10
- $78.20 → 20% is $15.64, so 18% is roughly $14.08
In practice, just leave close to 20% — the difference between 18% and 20% on a $50 bill is only $1.
25% — Divide by 4
Divide the bill by 4, or find 20% and add 10%/2.
- $45.00 ÷ 4 = $11.25
- $80.00 ÷ 4 = $20.00
The Rounding Trick
Round the bill to the nearest $10 before calculating. It's close enough and much easier:
- Bill is $47.30? Round to $50. 20% of $50 = $10. Close enough.
- Bill is $83.15? Round to $80. 20% of $80 = $16. Good estimate.
Pre-Tax vs. Post-Tax: Which Amount Do You Tip On?
This is one of the most common tipping questions.
Pre-tax (subtotal) — Traditional etiquette says tip on this amount. The tax goes to the government, not the server, so it shouldn't factor into the tip.
Post-tax (total) — Many people tip on this because it's the number right in front of them. Simpler math.
The real-world difference is small. On a $100 meal with 8% sales tax:
- 20% on pre-tax: $100 × 0.20 = $20.00
- 20% on post-tax: $108 × 0.20 = $21.60
The difference is $1.60. Either is perfectly acceptable. If you're aiming for great service acknowledgment, tipping on the post-tax amount is a small but easy way to be generous.
Standard Tipping Percentages by Service
Tipping norms in the US vary by the type of service:
Restaurants (Sit-Down)
- 15% — adequate service
- 18% — good service (many people's default)
- 20% — great service
- 25%+ — exceptional experience
For groups of 6 or more, many restaurants automatically add 18–20% gratuity. Check your bill before adding a second tip.
Bars
- $1–2 per drink for beer, wine, or simple mixed drinks
- $2–3 per drink for complex cocktails
- 15–20% of the tab if running a tab
Food Delivery
- 15–20% of the order total
- $3–5 minimum for small orders
- Tip higher in bad weather, for heavy items, or difficult access (apartments, stairs)
Takeout / Counter Service
- Not required, but 10–15% is generous
- $1–3 for simple orders
- More common since 2020; many POS systems now prompt for tips
Hairdressers and Barbers
- 15–20% of the service cost
- 20–25% for complex services (color, corrections, intricate styles)
Taxi and Rideshare
- 15–20% of the fare
- $2–3 minimum for short rides
- Tip extra for help with luggage
Hotel Housekeeping
- $2–5 per night
- Leave daily, not just at checkout (different staff may clean each day)
- Leave on the pillow or nightstand with a note so it's clearly a tip
Movers
- $20–50 per mover for a standard local move
- $50–100+ per mover for long, difficult, or multi-flight moves
How to Split a Bill with Tip
The simplest approach: calculate the tip first, add it to the bill, then divide.
Example: 5 friends share a $220 dinner and agree on 20% tip.
- Tip: $220 × 0.20 = $44.00
- Total: $220 + $44 = $264.00
- Per person: $264 ÷ 5 = $52.80 each
When People Ordered Different Amounts
If one person had a $15 salad and another had a $60 steak, equal splitting isn't always fair. Options:
- Each person tips on their own items — most equitable
- Split the tip evenly but pay for your own food — a compromise
- Use a split bill calculator to handle different amounts per person
The Rounding-Up Approach
To avoid awkward cents, round each person's share up to the next dollar. The server gets a slightly higher tip, and everyone has a clean number to pay.
$52.80 → $53.00 per person. Simple.
Common Mistakes
Tipping on discounted prices
If you used a coupon or received a discount, tip on the original (pre-discount) amount. The server did the same amount of work regardless of your coupon. On a $100 meal with a 50% off coupon, tip 20% of $100 ($20), not 20% of $50 ($10).
Double-tipping on automatic gratuity
For large groups, check if gratuity is already included on the bill. It usually appears as "service charge" or "gratuity." If it's there, you don't need to add more — though you can add a small extra amount for outstanding service.
Tipping on the full amount when there's a gift card
If you pay with a $50 gift card on a $70 bill, tip on the full $70 — not just the $20 you paid out of pocket.
Not tipping on drinks
Some people tip only on food and skip drinks. The standard practice is to tip on the entire bill including beverages (alcoholic and non-alcoholic). The server provides the same level of service for drinks as for food.
Tipping Outside the US
Tipping customs vary dramatically around the world:
Tip 15–20% (expected): United States, Canada
Tip 10–15% (common but flexible): United Kingdom (if no service charge), Mexico, Brazil, India
Round up or tip 5–10% (appreciated): Germany, France, Italy, Spain (service charge often included)
No tipping expected: Japan, South Korea, China, Australia, New Zealand, Singapore, most of Scandinavia
In Japan, tipping can actually be considered rude — it implies the service wasn't part of the professional standard. In Australia, servers earn a living wage, so tips are a bonus rather than an expectation.
Travel tip: When visiting a new country, research local customs before your trip. Hotel concierges and travel guides are good sources for local norms.
Why Tipping Exists in the US
The US tipping system exists because federal law allows a lower minimum wage for tipped employees ($2.13/hour federally, though many states require more). Tips make up the difference — often 50–80% of a server's total income.
This means that in the US, tipping isn't a bonus for good service — it's how servers earn their living. While opinions on this system vary, understanding it explains why tipping is a strong social expectation rather than an optional gesture.
Try It Yourself
Use the tip calculator to quickly calculate tips, totals, and per-person splits for any bill amount. Adjust the percentage with presets or a slider, set the number of people, and optionally round up to the nearest dollar.