ToolboxKit

How to Calculate a Tip: Easy Mental Math for 15%, 18% and 20%

The bill arrives, everyone looks at their phone, and nobody wants to do the math. You don't need a calculator for most tips. A couple of mental shortcuts get you there in seconds.

The 10% trick

The easiest starting point is 10%: just move the decimal point one place to the left.

  • Bill of $64.00 → 10% is $6.40
  • Bill of $82.50 → 10% is $8.25

From there, everything else is simple addition.

15%, 18% and 20% in your head

  • 20%: double the 10%. For $64.00, that's $6.40 × 2 = $12.80.
  • 15%: add half of the 10% to the 10%. For $64.00: $6.40 + $3.20 = $9.60.
  • 18%: take 20% and subtract a tenth of it. For $64.00: $12.80 − $1.28 = $11.52. Or round: about 2 dollars less than 20%.

Round the bill to a friendly number first. A $63.70 bill is close enough to $64 for a quick estimate, and no server will mind if you round the tip up.

How much should you tip?

In the United States, 15% to 20% is the usual range for table service, with 18% to 20% typical for good service. In the UK and much of Europe, a service charge of 10% to 12.5% is often added to the bill automatically, and extra tipping is optional. Customs differ by country, so check whether service is already included. Many other services, such as delivery, taxis and hairdressers, follow their own local norms.

Before or after tax?

Many people tip on the pre-tax subtotal, because tax isn't part of the service. Tipping on the total including tax is also common and simply gives a slightly larger tip. Both are acceptable. Pick one and stay consistent.

Splitting the bill with a tip

To split fairly, add the tip to the bill first, then divide by the number of people. For a $120 bill with a 20% tip, the total is $144; between four people, that's $36 each. If some people ordered much more than others, it's fairer to split by what each person ordered and divide the tip in proportion.

Rounding up

Rounding each person's share up to a whole amount makes paying easier and usually adds a little extra to the tip. That's why many tip calculators include a "round up" option.

Let the calculator do it

For exact numbers, use our Tip Calculator. Enter the bill, pick a percentage, set the number of people, and it shows the tip, the total and each person's share, right in your browser, with nothing stored or sent anywhere.