How Much to Tip, and How to Calculate It Fast

Tipping is simple arithmetic wrapped in social uncertainty. This guide covers both halves: the math, so you never have to guess, and the common conventions, so you know what is expected.

The Formula

Tip = bill × tip percentage ÷ 100

Total = bill + tip

Per person = total ÷ number of people

Say the bill is 86.40 and you want to leave 18%:

• Tip: 86.40 × 0.18 = 15.55 (15.552 rounded)
• Total: 86.40 + 15.55 = 101.95
• Split four ways: 101.95 ÷ 4 = 25.49 each

The Tip Calculator runs these three steps for any bill, percentage and group size.

Mental-Math Shortcuts

You rarely need a calculator if you remember that 10% is just a decimal shift.

• 10%: move the decimal one place left. 86.40 becomes 8.64.
• 15%: take 10%, then add half of it. 8.64 + 4.32 = 12.96.
• 20%: double the 10% figure. 8.64 × 2 = 17.28.
• 18%: take 20% and subtract a tenth of it (17.28 − 1.73 = 15.55).

Round to a convenient number afterwards. A tip that is a few cents off is perfectly fine.

Typical Tipping Ranges

Conventions differ widely, and they change over time, so treat these as rules of thumb rather than law.

• United States and Canada: 15 to 20% at sit-down restaurants is the usual range, with 20% increasingly common. Counter service, delivery, taxis, hair stylists and hotel staff each have their own norms.
• United Kingdom and much of Europe: often 10 to 12.5%, and frequently already added as a service charge. Check the bill before adding more.
• Japan and parts of East Asia: tipping is not customary and can cause confusion.
• India: many restaurants add a service charge to the bill. Where they do not, 5 to 10% is a common gesture for good service. Service charge is not a legal requirement for customers to pay in all cases, so check current rules if there is a dispute.

When travelling, a quick look at local guidance saves awkwardness.

Before or After Tax?

Many people tip on the pre-tax subtotal, because the tax is not a measure of service. Others tip on the full total for simplicity. Either is acceptable. If your bill shows both figures, pick one approach and stay consistent. The difference is small: on a 100 subtotal with 8% tax, a 20% tip is 20.00 on the subtotal or 21.60 on the total.

Splitting a Bill

Splitting evenly is easy: divide the total by the number of people. It becomes unfair when one person ordered much more than the others. Two fair approaches:

• Split the tip evenly, pay for your own items. Add each person's food, then split the tip by share of the subtotal.
• Split by share of the subtotal. If you ordered 30% of the food, you cover 30% of the tax and tip.

In a group, agree on the method before the bill arrives.

Rounding

Rounding the total up to a whole number is a common way to leave a slightly larger tip with no extra math. Rounding the tip itself to the nearest whole currency unit works well in cash. Just keep the final amount reasonable relative to the bill.

Common Mistakes

• Adding a tip on top of an included service charge.
• Calculating the tip on the post-discount amount when the server worked at the full price. Many people tip on the pre-discount total for that reason.
• Forgetting to divide the tip as well as the bill when splitting.
• Mixing up 1.15 (a multiplier for bill plus tip) with 0.15 (the tip alone).

A Shortcut Worth Remembering

To get the total in one step, multiply the bill by 1 plus the tip rate. For 18%, multiply by 1.18. For the bill above, 86.40 × 1.18 = 101.95, with no separate tip step.

For quick answers while you are at the table, open the Tip Calculator, enter the bill and the number of people, and read off what everyone owes.