Tip on the pre-tax or post-tax amount? The math
Quick answer
Tip on the pre-tax amount. Emily Post's tipping guide lists 15 to 20 percent of the pre-tax amount for sit-down service, and its Finer Points page says it is acceptable to tip on the pre-tax amount. Tipping on the total instead adds the tip rate times the tax, which is $1.20 on a $100 check with 6 percent tax and a 20 percent tip.
Key points
- Emily Post lists the sit-down tip as 15 to 20 percent of the pre-tax amount and calls a pre-tax tip acceptable.
- The gap between the two bases is the tip rate times the tax. On a $100 check with 8.875% tax and a 20% tip, it is $1.78.
- On a split check, agree the base once for the whole table and figure the tip on the full check, not person by person.
- If the receipt has no separate tax line, there is only one number to tip on.
On this page
Do you tip on the pre-tax or post-tax amount?
Tip on the pre-tax amount, which is the base Emily Post names. Tipping on the total instead adds the tip rate times the tax, which is a small amount on a normal check. The rest of this page shows how small, and what to do when a table splits the check.
What does Emily Post say?
As of October 2026, Emily Post’s tipping guide lists 15 to 20 percent for sit-down wait service, figured on the pre-tax amount. Its Finer Points of Tipping page puts it as a heading: “It is acceptable to tip on the pre-tax amount of the bill.” The next sentence reads: “For large parties this can be quite different than the total.”
So a tip on the pre-tax subtotal follows that guidance, and a tip on the total leaves a little more. The next section puts a number on “a little”.
How big is the difference?
The gap is the tip rate times the tax. Take a $100.00 check before tax with 6 percent tax. The tax is $6.00. A 20 percent tip on the pre-tax amount is $20.00, and a 20 percent tip on the total of $106.00 is $21.20. The difference is $1.20, which is 20 percent of the $6.00 tax.
These tables show the gap for five tax rates and three pre-tax check sizes. The check sizes are the subtotal before tax, and the amounts are rounded to the cent.
At a 20 percent tip, a $100 check gains between $0.80 and $2.00 when you tip on the total.
| Tax rate | $50 check | $100 check | $250 check |
|---|---|---|---|
| 4% | $0.40 | $0.80 | $2.00 |
| 6% | $0.60 | $1.20 | $3.00 |
| 8.25% | $0.83 | $1.65 | $4.13 |
| 8.875% | $0.89 | $1.78 | $4.44 |
| 10% | $1.00 | $2.00 | $5.00 |
At an 18 percent tip, every gap is 90 percent of the 20 percent figure, give or take a cent of rounding.
| Tax rate | $50 check | $100 check | $250 check |
|---|---|---|---|
| 4% | $0.36 | $0.72 | $1.80 |
| 6% | $0.54 | $1.08 | $2.70 |
| 8.25% | $0.74 | $1.49 | $3.71 |
| 8.875% | $0.80 | $1.60 | $3.99 |
| 10% | $0.90 | $1.80 | $4.50 |
What changes when the check is split?
The wrinkle is that each person has to use the same base, and a split check makes that easy to miss. Say four friends have a $120.00 subtotal and 8.875 percent tax, which is $10.65. The tip at 20 percent is $24.00 on the pre-tax amount or $26.13 on the $130.65 total. That is a $2.13 gap for the table, about 53 cents a person.
The trouble starts when people figure their own tips. If each person tips 20 percent of their $30.00 pre-tax share, each leaves $6.00. If each tips on a post-tax share of $32.66, each leaves $6.53, and four of those come to $26.12, one cent under the table’s $26.13. If two people use one basis and two use the other, the tip lands at $25.06, which matches neither $24.00 nor $26.13.
The fix is to agree on the base once, figure the tip on the full check, and divide the total. A total of $154.65 with the tip on pre-tax splits into three shares of $38.66 and one of $38.67. The split bill calculator with tax and tip shows both bases side by side, so the table can see the gap before choosing.
What if the receipt has no separate tax line?
Then there is only one number to tip on. Some menus list prices that already include tax, and the receipt prints one total with no tax line. In that case the pre-tax and post-tax amounts are the same figure, and the choice goes away.
If the check includes a service charge or an automatic gratuity, the tip may already be in the total. Service charge versus tip explains how the two differ, and automatic gratuity on large parties covers how to split it.
What should you do next?
Decide the base before the check arrives, and say it once: “Let’s tip 20 percent on the subtotal.” Then split the total the way the table prefers. For the splitting itself, four ways to split a restaurant bill runs one check through each method. If you log the meal in EvenOut, enter the total with the tip already included, then choose “Equally” or another split, and EvenOut shares any leftover cent instead of losing it.
Frequently asked questions
What does Emily Post list for a buffet or a bar tab?
Emily Post's tipping guide lists 10 percent of the pre-tax amount for buffet wait service. For a bartender it lists $1 to $2 per drink or 15 to 20 percent of the tab.
How do you find the pre-tax amount when the receipt shows only a total?
Divide the total by 1 plus the tax rate. A $108.00 total with 8 percent tax is $108.00 divided by 1.08, which is $100.00. Many receipts print a subtotal line, so look for it first, and tip on that number.
Does the gap grow with the size of the check?
In a straight line. The gap is the check times the tax rate times the tip rate, so a $250 check has five times the gap of a $50 check at the same rates. At 10% tax and a 20% tip, that is $5.00 against $1.00.
What if the table cannot agree on a base?
Use the pre-tax amount, which is the one Emily Post names, and let anyone who wants to leave more add it on top of their own share. The table's tip stays one number, and the extra is a choice instead of a debate.
Sources
Checked October 6, 2026.
Keep reading
- Calculator Split bill calculator with tax, tip and discount Enter the subtotal, discount, tax and tip to split one bill equally. See the tip on the pre-tax and post-tax amount side by side, to the cent.
- Glossary Service charge vs tip, and what 'gratuity included' means A tip is your choice. A service charge is a fee the restaurant adds. If the check says gratuity included, it is in the total: $148 of food becomes $189.44.
- Guide Automatic gratuity on large parties: how to split it When the check already has 18% gratuity for a large party, read the line, split it across 8 people three ways, and decide whether extra is needed.
- Guide How to split a restaurant bill: 4 fair methods Four ways to split a restaurant bill, run on one $184 check for five people, with each person's total, when each method is fair and what to say before ordering.