Illustration of a 64.80 dollar bill with a 10% tip of 6.48 dollars doubled to a 20% tip of 12.96 dollars

Calculators & everyday math

How to Calculate a Restaurant Tip in Your Head

You don’t need a phone to work out a tip. A couple of mental steps get you to any common percentage in seconds, and a few habits help you land on a sensible round number. This guide covers the shortcuts, what amount to tip on, and how to round.

Ready to try the tool this guide describes?

Start with 10%

Move the decimal point one place to the left. On a $64.80 bill, 10% is $6.48. Every other shortcut builds on this number.

Common percentages from 10%

Common percentages from 10% comparison
TipHowOn $64.80
10%Move the decimal point$6.48
15%10% plus half of it$9.72
18%20% minus 2% (2% is a fifth of 10%)$11.66
20%Double 10%$12.96
25%A quarter of the bill$16.20

What to tip on

Some people tip on the subtotal before tax and others on the full bill; customs differ between countries and between people. Whichever you choose, enter that amount in the Tip Calculator — it tips on exactly the amount you give it. If you used a coupon, some people tip on the amount before the discount, since the service was the same.

Rounding

  • Round the tip rather than the total if you want to stay close to the percentage you chose.
  • Or round the total up to a whole number and let the tip absorb the difference: $64.80 + $12.96 = $77.76, rounded up to $78.
  • On larger bills, rounding to a whole dollar barely changes the percentage.

When the calculator helps

Mental shortcuts are fine for one person. When you are splitting between several people, choosing an unusual percentage, or want the total to the cent, the Tip Calculator does the arithmetic and tells you if the split leaves a stray cent.

Calculate a Tip FAQ

What is the easiest way to work out a 20% tip?
Find 10% by moving the decimal point one place left, then double it. On $45, 10% is $4.50, so 20% is $9.
How do I calculate a 15% tip?
Find 10% and add half of it again. On $60: $6 + $3 = $9.
Should I tip on the amount before or after tax?
Customs vary and both are common. The arithmetic is the same — just decide which amount to start from.
Is the tip worked out before or after a discount?
Some people tip on the original amount because the service was the same; others tip on what they paid. It is a personal choice.
How should I round a tip?
Round either the tip or the total to a convenient number. Rounding a $77.76 total up to $78 adds 24 cents to the tip.

Related guides

Open the tool

Jump into Tip Calculator when you are ready to process your files.

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