How to Calculate a Restaurant Tip (15%, 18%, 20% and Split Bills)

Leaving a fair tip is part of dining out in many countries—especially in the United States, where service staff often rely on gratuity. The math is simple once you know the formula. This guide walks through how to calculate a restaurant tip, choose a reasonable percentage, and split the bill when you eat with friends.

The basic tip formula

A tip is a percentage of the bill before tax (most people use the pre-tax subtotal; some use the total with tax—pick one approach and stay consistent).

Tip amount = bill × (tip percent ÷ 100)

Total to pay = bill + tip amount

Example: 18% tip on an $85 bill

1. Convert the percent: 18 ÷ 100 = 0.18
2. Multiply: 85 × 0.18 = $15.30 tip
3. Add: 85 + 15.30 = $100.30 total

That is the entire calculation. Any tip calculator—including our free tip calculator—does these two steps for you.

Common tip percentages in the US

There is no single legal rule, but these ranges are widely used at sit-down restaurants:

• 15% — baseline for acceptable service
• 18% — very common for good service (often the “suggested” line on receipts)
• 20% — strong service or special occasions
• 22–25% — exceptional service or high-end dining

For quick mental math, you can use shortcuts:

• 10% = move the decimal left one place ($85 → $8.50)
• 20% = double the 10% amount ($8.50 × 2 = $17)
• 18% ≈ 20% minus a little, or use a calculator for exact cents

Coffee shops, takeout counters, and food trucks may use smaller tips or none at all—follow local custom.

Should you tip on tax?

Many diners calculate tip on the food and drink subtotal before sales tax. Others tip on the final total including tax. The difference is usually small:

• Subtotal $85, tax $7 → tipping 18% on $85 = $15.30; on $92 = $16.56

Either method is acceptable if you are consistent. When in doubt, tipping on the pre-tax subtotal is a common choice.

How to split the bill with tip

When several people share one check, you usually want each person’s share of the total including tip.

Per person = (bill + tip) ÷ number of people

Example: $96 bill, 20% tip, 2 people

• Tip: 96 × 0.20 = $19.20
• Total: 96 + 19.20 = $115.20
• Each pays: 115.20 ÷ 2 = $57.60

Some groups split only the food evenly and leave a shared tip in cash—that works too, but the formula above is the fairest when everyone pays electronically.

Tipping on discounted bills or with coupons

Always calculate the tip on the price of the food before discounts, unless your group agrees otherwise. If a $100 meal is reduced to $80 with a coupon, tipping 18% on $100 ($18) is often considered fair to the server who served the full meal.

International travel

Tipping customs vary:

• United States / Canada — 15–20% at table service is standard.
• United Kingdom — service charge may be included; check the receipt.
• Europe — service is often included; small change or 5–10% extra is common in some countries.
• Japan — tipping is often not expected and can cause confusion.

When traveling, look up local norms before you pay.

Quick reference table

When to use a tip calculator

Mental math is fine for round bills, but a calculator helps when:

• The bill has an odd total (e.g. $47.83)
• You need exact change on a card payment
• You are splitting among 3, 4, or more people
• You want to compare 15% vs 18% vs 20% quickly

Use our tip calculator: enter the bill, set the tip percent, enter the number of people, and tap Calculate tip. You will see the tip amount, total with tip, and per-person share.

For other percent problems (tax, discounts, test scores), try the percentage calculator.

Frequently asked questions

Do you tip on alcohol?
Many people tip on the full bill including drinks; some tip a slightly lower rate on expensive wine—this is personal preference.

What if service was poor?
You can reduce the tip or speak with a manager, but leaving zero without explanation is rare for sit-down service in the US.

Are automatic gratuity charges tips?
Parties of six or more may have auto-gratuity on the receipt. That is already a tip; you may add extra for great service but are not required to double-tip.

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Bottom line: Multiply the bill by your tip percent divided by 100, add that to the bill, and divide by the number of people if you are splitting. For fast, accurate results, use the free tip calculator.