How to Calculate a Tip
Tip, total, and per-person split with pre-tax versus post-tax bases, a 15–20% table, and what to do when service is already included.
By Ricardo Rodrigues · 6 min read · Updated
A tip is a percentage of a bill, then a decision about whose bill. The arithmetic is short. The arguments are about the base (before tax or after), the rate (local custom), and the split (equal heads or equal dishes). PercentBox’s tip calculator does the arithmetic for a rate, a bill, and a headcount. This page is about not feeding it the wrong bill.
The two lines you actually want
Tip = bill × (rate / 100)
Total = bill + tip = bill × (1 + rate / 100)
Per person, if you split evenly = total / people
18% on €64.50. Tip = 64.50 × 0.18 = €11.61. Total = €76.11. Two people pay €38.06 each if you round the last cent onto one person, or €38.055 if you pretend coins divide forever. In cash, someone pays an extra cent. That is not a math failure.
20% on €40. Tip = €8. Total = €48. Clean numbers are how you notice a wrong key: if the calculator says the tip is €18, you doubled the bill in your head and you know to look again.
15% on €100, split 4 ways. Tip = €15. Total = €115. Each share = €28.75.
A small table worth keeping
On a €50 pre-tip bill:
| Rate | Tip | Total | Each, split by 2 | Each, split by 3 |
|---|---|---|---|---|
| 10% | €5.00 | €55.00 | €27.50 | €18.33 |
| 15% | €7.50 | €57.50 | €28.75 | €19.17 |
| 18% | €9.00 | €59.00 | €29.50 | €19.67 |
| 20% | €10.00 | €60.00 | €30.00 | €20.00 |
| 25% | €12.50 | €62.50 | €31.25 | €20.83 |
Three-way splits create repeating cents. €59 / 3 = €19.666…. Two people pay €19.67 and one pays €19.66, or you round the total to a splittable number by adjusting the tip a few cents. Do that openly. Silent rounding is how friends decide the calculator is “wrong.”
For an ugly bill, build 15% or 20% from 10% as in mental math for percentages, then confirm with the tool if the total will be written down.
Pre-tax or post-tax
Imagine a €50 meal and €5 of sales tax or VAT shown separately, so the card slip says €55.
- Tip 20% on the meal: 0.20 × 50 = €10. Total paid including tax = 55 + 10 = €65.
- Tip 20% on the slip: 0.20 × 55 = €11. Total = €66.
One euro, on this bill. On a €400 dinner the same choice is €8. Neither is a law of percentages. In the United States, custom is often described as a percent of the pre-tax restaurant bill, commonly in a 15–20% band, with 18–20% treated as a solid default when service was good. Local habit varies by city, and delivery apps add their own suggested buttons, which are sometimes calculated on a total that already includes fees.
In much of Europe, menu prices are service-inclusive wages-plus-tips are not the same social script. A percent on top can be a thanks, not an obligation. If a service charge is already on the bill, you are looking at a fee the venue added. Treating it as the subtotal for a second full tip double-counts the same idea. Read the words “service included,” “gratuity,” and “suggested tip” as different lines.
VAT muddies the printed total in a specific way. If prices on the menu already include 23% VAT, there may be no separate tax line to exclude. Your “pre-tax” figure is not shown. You would have to extract the VAT to tip only on the net, which almost nobody does at the table, and which is an odd thing to do if the custom is “a percent of what I was charged for the food.” When tax is not a separate line, tip on the amount you are actually staring at, unless you have a reason not to.
Uneven orders
Four people. Three ate pasta at €16, one ordered the €42 tasting menu, and you shared €10 of dessert. Subtotal €100. A 20% tip is €20, total €120.
Equal split: €30 each. The pasta eaters subsidize the tasting menu. That can be a deliberate “we’re out together” rule. It should not be a surprise.
Split by food, tip on each share: Each pasta diner’s food-plus-share-of-dessert needs a rule for the dessert. Say dessert is €2.50 each. Pasta person owes €18.50 before tip, then 20% is €3.70, total €22.20. The tasting menu is €44.50 before tip, tip €8.90, total €53.40. Sum of tips = 3 × 3.70 + 8.90 = €20. Good, the tip is conserved. The headache is the shared dessert, not the percent.
A practical compromise: split anything shared equally, compute one tip on the grand subtotal, and allocate that tip in proportion to each person’s unshared food. Proportional allocation is another percentage: person share / subtotal × tip. For the tasting menu, 42/100 × 20 = €8.40 of the tip, slightly different from the “tip on my own plate including dessert” version. Pick a rule before the card machine, not during it.
Suggested buttons and double tipping
Card machines that flash 15 / 20 / 25 are applying those rates to whatever amount was sent to the machine. If the server already added a tip line, and you also press 20%, you tip twice. If a delivery app added a €4 service fee and the suggested tip is on (food + fee + tax), your “18%” is 18% of a larger base than the food. That may be what you want. It is rarely what people think they pressed.
Do one slow multiplication before you press. 20% of €64 is about €13. If the button says €22, something else is in the base, or the rate is not 20%. What is 20% of the number on the screen is the entire check.
Rounding, cash, and minimums
Cash tips get rounded because coins are annoying. Rounding €11.61 to €12 is a slightly higher rate (12/64.50 ≈ 18.6%), not a different formula. Rounding down to €10 is about 15.5%. Name it as a rounded amount if you like; just do not call €10 “the 18%” afterward.
Some places have a suggested minimum that is a fixed amount on small bills, because 15% of a €3 coffee is a coin that does not match the labor. A fixed amount is not a percentage. Do not convert it back into a percent and then feel you have discovered a rule for larger bills.
When to use the tip calculator
Use it when the bill is uneven, the split is more than two, or you are comparing 15, 18, and 20 before the card machine times out. Use it to show the per-person line so the argument is about the rate, not about mental division.
Do not use it to learn the local custom. The custom is not in the formula. Decide the rate and the base first — pre-tax if a tax line exists and that is your rule, full amount if it does not — then let the calculator multiply. If service is already charged, decide whether you are adding anything at all before you type a percent.
FAQ
- Should I tip on the tax?
- Where tipping is a custom on the meal, many people use the pre-tax subtotal, and some use the full bill. Pick one rule and stay with it. The percent is not a law; the base you choose changes the euros more than arguing over 18 versus 20 once the bill is small.
- How do I split an uneven tip fairly?
- Compute one tip on the whole bill, add it, then split the grand total by headcount if you shared equally. If people ordered very different amounts, split the pre-tip subtotals first and let each person tip on their own share.
- What if the receipt already has a service charge?
- A mandatory service charge is not a tip you still owe, unless you intend an extra. Read the line. In many European restaurants the printed prices already assume staff are paid a wage, and an extra percent is optional rather than expected.