How to calculate a tip
A tip is a plain percentage of the bill:
tip = bill × (percentage ÷ 100)
On a $45 bill, a 10% tip is $4.50 and an 18% tip is $8.10. Whether you calculate on the pre-tax or post-tax total is a matter of local convention; in the United States either is considered acceptable, and the difference is usually under a dollar.
The mental shortcut
Find 10% by moving the decimal point one place left, then build from there. On a $86 bill, 10% is $8.60, so 15% is $8.60 + $4.30 = $12.90 and 20% is $17.20. Almost every tip you will ever need is a combination of 10%, half of 10%, and double 10%.
Splitting the bill
Divide the total including tip by the number of people. Rounding each share up to the nearest whole unit is the usual way to avoid ending up short.
Tipping customs around the world
Tipping norms vary widely, and over-tipping in a country that does not expect it can be as awkward as under-tipping in one that does.
| Country | Restaurant norm | Notes |
|---|---|---|
| United States | 15–20% | Expected; staff wages assume it |
| Canada | 15–20% | Similar to the US |
| United Kingdom | 10–12.5% | Often already added as a service charge |
| France | Rounding up | Service is included by law |
| Germany | 5–10% | Round up to a convenient figure |
| Italy | 0–10% | A cover charge often replaces the tip |
| Spain | 0–10% | Small change is normal |
| Brazil | 10% | Usually printed on the bill |
| Japan | None | Tipping can cause offence |
| Australia | 0–10% | Optional, for good service |
Always check the bill before adding a tip — a service charge may already be included, in which case an extra gratuity is entirely optional.
Frequently Asked Questions
- How much is a 20% tip on $50?
- $10. Take 10% of the bill ($5) and double it.
- Should I tip on the pre-tax or post-tax amount?
- Either is acceptable in the US. Tipping on the pre-tax subtotal is the stricter convention and costs slightly less.
- What if a service charge is already on the bill?
- Then the tip has been collected for you. Anything extra is discretionary and usually reserved for exceptional service.