How to Calculate a Restaurant Tip
A tip percentage is the amount you choose to tip on multiplied by the percentage written as a decimal. Once you know a few shortcuts, most common restaurant tips are easy to estimate without a calculator.
The basic tip formula
Tip = Amount × Tip Percentage
Convert the percentage to a decimal before multiplying. For example, 20% becomes 0.20 and 18% becomes 0.18.
Common tip percentages
| Tip rate | Calculation | $50 bill | $100 bill |
|---|---|---|---|
| 10% | Bill × 0.10 | $5.00 | $10.00 |
| 15% | Bill × 0.15 | $7.50 | $15.00 |
| 18% | Bill × 0.18 | $9.00 | $18.00 |
| 20% | Bill × 0.20 | $10.00 | $20.00 |
| 25% | Bill × 0.25 | $12.50 | $25.00 |
How to calculate a 10% tip
Move the decimal point one place to the left. On an $86 bill, 10% is $8.60. On a $125 bill, 10% is $12.50.
How to calculate a 20% tip
Find 10%, then double it. For an $86 bill, 10% is $8.60, so 20% is $17.20.
20% example
$80 × 0.20 = $16.00
The total including tip is $96.00.
How to calculate a 15% tip
Find 10%, then add half of that amount. On an $80 bill, 10% is $8.00. Half of $8.00 is $4.00. Together, that gives a 15% tip of $12.00.
How to calculate an 18% tip
One quick method is to calculate 20% and subtract 2%. For an $80 bill, 20% is $16.00. Two percent is $1.60, so 18% is $14.40.
You can also calculate 10% plus 5% plus 3%. Choose whichever method is easiest for the number in front of you.
How to calculate a 25% tip
A 25% tip is one quarter of the amount. Divide the bill by four. On an $80 bill, $80 ÷ 4 = $20.
More worked examples
| Bill | 15% | 18% | 20% | 25% |
|---|---|---|---|---|
| $25 | $3.75 | $4.50 | $5.00 | $6.25 |
| $50 | $7.50 | $9.00 | $10.00 | $12.50 |
| $75 | $11.25 | $13.50 | $15.00 | $18.75 |
| $100 | $15.00 | $18.00 | $20.00 | $25.00 |
| $150 | $22.50 | $27.00 | $30.00 | $37.50 |
Should the tip be calculated before or after tax?
Some diners use the pre-tax subtotal and others use the after-tax amount. The difference can be small on an individual meal but more noticeable on a large bill. Quick Dine Split supports both approaches.
Before-tax and after-tax comparison
Pre-tax subtotal: $100.00
After-tax amount: $108.00
20% tip before tax: $20.00
20% tip after tax: $21.60
For a fuller comparison, read Should You Tip Before or After Tax?
Check for automatic gratuity first
Before adding a tip, look at the receipt for words such as gratuity, service charge, or service fee. Some restaurants automatically add a gratuity, especially for larger parties. If a tip is already included, decide whether you intend to add anything extra before calculating another percentage.
Rounding a tip
There is no requirement to create awkward cent amounts when you are estimating a voluntary tip. Some people round the tip or final total to a convenient amount. If you do round, check the resulting percentage if that matters to you.
For example, an 18% tip on $47.80 is $8.604. Rounded to the nearest cent, that is $8.60. Rounding the tip to $9.00 would be about 18.8%.
Splitting the bill after tipping
If several people are sharing the meal equally, first settle the bill, tax, and tip, then divide the final amount. Quick Dine Split handles the full sequence and correctly distributes any leftover cents.