A tip is a percentage of what the food and service cost, and the conventional base for that percentage is the bill before sales tax. Tipping on the tax-inclusive total quietly adds a tip on the tax as well, which on an 8% tax rate makes an 18% tip closer to 19.5%. This calculator strips the tax out first, applies the percentage, and adds it back.
Tipping conventions vary enormously and there is no arithmetic that resolves that. In the United States 15% to 20% at a sit-down restaurant is normal; in much of Europe rounding up or 5% to 10% is generous; in Japan it can cause offence. The percentage is an input here for that reason, and the tax rate is too, since it differs by city as well as by country.
On the defaults, a $84.60 bill including 8.25% tax has a pre-tax amount of $78.15. A 18% tip on that is $14.07, giving a total of $98.67. Split 3 ways that is $32.89 each.
The formula
bill- Total on the bill, including tax
tax rate- Sales tax already inside the bill
tip %- The percentage you want to leave
people- Number splitting the total
How to use this calculator
- Enter the bill total as printed, including tax.
- Enter the sales tax rate so it can be excluded from the tip base.
- Set the tip percentage you want to leave.
- Enter how many people are splitting it; the gauge shows the tip amount.
Worked examples
18% on a $84.60 bill
$84.60 ÷ 1.0825 = $78.15 before tax. 18% of that is $14.07, so the total is $98.67. Tipping on the full $84.60 instead would have cost $15.23 — $1.16 more for no extra service.
Splitting unevenly
Split 3 ways the total is $32.89 each. Rounding up to $33.00 per person collects $99.00, leaving $0.33 over — a simple way to round the tip up without arithmetic at the table.
How to read your score
Frequently asked questions
Should I tip on the pre-tax or post-tax amount?
Convention says pre-tax, since the tax is not part of what you were served. The difference is small on any one bill but consistent, and either choice is defensible — what matters is knowing which you are doing.
What if service is already included?
Then no further tip is expected. Look for a service charge or "gratuity included" line, which is common for larger groups and in many countries by default. Tipping on top of it is optional generosity, not an obligation.
How much should I tip?
It depends entirely on the country and the setting, which is why the percentage is an input. In the United States 18% to 20% is standard for table service; in much of Europe rounding up is normal; in several Asian countries tipping is not customary at all.
Should I tip on delivery fees?
The fee usually goes to the platform rather than the driver, so most people tip on the food total and treat the fee separately. If a service charge is explicitly passed to the driver, that is different.
Does the tip percentage apply to alcohol?
By convention yes, on the full pre-tax bill including drinks. Some people tip a lower percentage on expensive wine on the grounds that the service is identical, which is a common but not universal view.
Tip reference
| Bill (with tax) | Pre-tax base | 15% tip | 18% tip | 20% tip |
|---|---|---|---|---|
| $25.00 | $23.09 | $3.46 | $4.16 | $4.62 |
| $45.00 | $41.57 | $6.24 | $7.48 | $8.31 |
| $84.60 | $78.15 | $11.72 | $14.07 | $15.63 |
| $120.00 | $110.85 | $16.63 | $19.95 | $22.17 |
| $200.00 | $184.76 | $27.71 | $33.26 | $36.95 |
Tips are calculated on the pre-tax base, which is the bill divided by one plus the tax rate.