How to Calculate a Tip: 5 Easy Methods (With Examples)

The check lands on the table, everyone is chatting, and you are the one who has to work out the tip. It does not need to be stressful. Every tip, whatever the percentage, comes from one small piece of arithmetic, and once you know a couple of shortcuts you can do it in your head in a few seconds.

Below are five methods, from the quickest mental trick to the exact formula. We will use the same bill throughout so you can see how each one works: a dinner check of $64.80.

The basic tip formula

Everything starts here. A tip is simply a percentage of the bill:

Tip = Bill × (Tip % ÷ 100)   |   Total = Bill + Tip

So an 18% tip on $64.80 is 64.80 × 0.18 = $11.66 (rounded to the cent), and the total you pay is $76.46. If you prefer to skip the arithmetic, the ppera tip calculator does it instantly, splits the bill and can round the result for you.

Method 1: The "move the decimal" trick for 10%

Ten percent is the foundation of almost every mental tip calculation. To find it, move the decimal point one place to the left.

• $64.80 becomes $6.48
• $23.00 becomes $2.30
• $118.50 becomes $11.85

Once you have 10%, the other common percentages are only one small step away.

Method 2: Build 15%, 20% and 25% from 10%

Start from the 10% figure and combine it:

For an 18% tip, find 20% and take away 2%. Two percent is one fifth of your 10% number, so here it is about $1.30. That gives $12.96 − $1.30 = $11.66, which matches the exact formula.

Method 3: Round first, then calculate

If the bill has awkward cents, round it to the nearest easy number before you start. $64.80 is close enough to $65 for a tip. Twenty percent of $65 is $13, so you would leave about $13. You will be off by a few cents at most, and usually in the server's favor, which nobody minds.

This works especially well for 20%: round the bill, drop the last digit, and double it. A $38.70 bill rounds to $39, 10% is $3.90, and 20% is $7.80.

Method 4: Use your phone's calculator in one step

Instead of calculating the tip and then adding it, multiply the bill by 1 plus the tip as a decimal. This gives the total in a single step:

• 15% tip: multiply by 1.15
• 18% tip: multiply by 1.18
• 20% tip: multiply by 1.20

For our example, 64.80 × 1.18 = 76.464, so you would write $76.46 on the receipt. If you only want the tip itself, multiply by 0.18 instead.

Method 5: The "double the tax" shortcut (US only)

Many Americans glance at the sales tax line and double it. Because sales tax in a lot of cities sits roughly between 7% and 10%, doubling it lands somewhere between 14% and 20%. In New York City, for example, the combined sales tax is 8.875%, so doubling it gives a tip of about 17.75%.

It is a handy sanity check, but it depends entirely on where you are. In a state with low or no sales tax, doubling the tax produces a tip that is far too small, so treat this as a rough guide only.

Should you round the total?

Rounding up to a whole number makes paying easier, especially when you are leaving cash or splitting with friends. Rounding $76.46 up to $77 turns the tip into $12.20, which is roughly 18.8%. Our calculator has a round up option that rounds the tip, the total or each person's share, and it shows you the effective percentage after rounding so there are no surprises.

Quick rule: if you are unsure, 20% of the pre-tax bill for good table service is widely seen as a fair, generous tip in the United States.

Common mistakes to avoid

• Tipping twice. Check whether a gratuity or service charge has already been added, which is common for large groups. If it has, an extra tip is optional.
• Tipping on a discounted amount. If you used a coupon or a dish was comped, most people tip on what the meal would have cost before the discount, because the server did the same work.
• Forgetting the split. When friends pay separately, make sure everyone covers their share of the tip as well as the food. Our guide to splitting the bill fairly walks through the options.

Putting it together

You do not need to be a math whiz to tip correctly. Remember three things: find 10% by moving the decimal, double it for 20%, and add half for 15%. For anything more precise, or when you need to divide the total between several people, use the tip calculator and let it do the work.