About the Tip Calculator
Tipping is arithmetic done badly, in poor light, after a glass of wine, while five people wait for you to finish. It is also arithmetic that is slightly awkward on purpose: 18% of 73.40 is not a figure most people reach for in their head, and the moment you divide it four ways the rounding starts to bite.
This calculator does the whole thing at once. It works out the tip at whatever rate you choose, adds it to the bill, splits the total between however many people are paying, and shows the per-person figure large enough to read across a table. If you want each share rounded up to a whole note or coin, it will do that too and tell you what the rounding cost.
Everything happens in your browser. No bill amount is sent anywhere.
How to Use the Tip Calculator
Enter the bill amount. Whether you use the figure before or after tax is up to you — see the FAQ below, because reasonable people differ on this.
Set the tip percentage. It starts at 15%, which is a middling default rather than a recommendation; local custom matters far more than any default we could pick. Common rates are 10%, 15%, 18% and 20%, and you can type any figure between 0 and 100.
Enter how many people are splitting the bill. Leave it at 1 if you are paying alone.
Tick round up if you want each person's share rounded up to a whole unit. This is the usual move when everyone is paying cash and nobody has coins.
The currency selector at the top changes the symbol and number formatting. It is a display setting only — it does not convert between currencies, because doing that properly needs live exchange rates, and a stale rate presented as a live one is worse than no conversion at all. Your choice is remembered on this device.
Press Calculate. You get the per-person amount as the headline figure, with the tip and the grand total beneath it, and the working shown step by step.
How a Tip Is Calculated
A tip is a percentage of the bill, so it is the same calculation as any other percentage of a number: divide the rate by 100 to turn it into a decimal, then multiply by the bill.
An 18% tip on 73.40 becomes 0.18 x 73.40 = 13.21. Add that to the bill and the total is 86.61. Split four ways, each person pays 21.65 — with one cent left over, which is where rounding comes in.
The order of operations matters more than it looks. This calculator rounds to whole cents once, at the end, rather than rounding the tip first and then dividing. If you round the tip to 13.21 and then divide 86.61 by four, you get 21.6525, which displays as 21.65. Four lots of 21.65 is 86.60 — a cent short of the total. Rounding early is how a bill quietly fails to add up, and it is exactly the sort of thing somebody at the table will notice.
Tip Formula
tip = bill x (rate / 100)
total = bill + tip
per person = total / number of peopleWith rounding up:
per person = ceiling( total / number of people )The ceiling function rounds up to the next whole unit, never down. That is deliberate: rounding down would leave the table short of the total, which means somebody is covering the gap without knowing it.
Step-by-Step Example
Four people have dinner. The bill is 100. They want to leave 15% and split it evenly.
Step 1 — work out the tip. 15 / 100 = 0.15, and 0.15 x 100 = 15. The tip is 15.
Step 2 — add it to the bill. 100 + 15 = 115. That is what leaves the table.
Step 3 — divide by the number of people. 115 / 4 = 28.75. Each person pays 28.75.
Now suppose everyone is paying cash and nobody wants to deal with coins. Tick round up, and each share becomes 29. Four lots of 29 is 116, so the table has left 16 rather than 15 — an effective tip of 16%, and one unit of change that comes back to the table or stays on it, as you prefer.
Understanding Your Result
The large figure is what one person pays. It is the number you actually need at the moment of paying, which is why it gets the headline rather than the total.
Below it, tip is the gratuity on its own, and total including tip is what the table is paying altogether. Those two are the numbers to check against the bill before anybody hands over a card.
If you ticked round up, the per-person figure is the rounded one, but the tip and total shown are the unrounded amounts. The difference between the rounded shares and the stated total is the extra that rounding added — usually small, occasionally a whole unit per person when the split is awkward.
When Should You Use This Calculator?
The obvious case is a restaurant bill, but the same arithmetic covers most situations where a percentage is added and then shared.
Splitting anything evenly — a group taxi, a shared delivery order, a round of drinks. Set the tip to 0 and it becomes a plain bill splitter.
Checking a bill you have been handed. If a restaurant has already added a service charge and printed a "suggested tip" on top, running the numbers takes ten seconds and occasionally saves a surprising amount.
Budgeting before you go out. If you know roughly what dinner costs, adding the tip in advance gives you the real figure rather than the menu one.
Working out what a rate actually costs. The gap between 15% and 20% on a small bill is trivial; on a large one it is a meal. Running both tells you whether the difference is worth thinking about.
Common Mistakes
Tipping on a bill that already includes service. This is the most expensive mistake on the list. A 12.5% service charge plus a 15% tip is nearly 28%. Read the itemised bill, not just the total.
Splitting before adding the tip. Dividing the bill first and then asking everyone to add their own tip produces a different — and usually lower — total than adding the tip and dividing once, because everyone rounds their own share down. Add first, split second.
Rounding the tip to a neat number and then dividing. Neat tips are fine when one person pays. When several people split it, a rounded tip rarely divides evenly, and the shares stop adding up to the total.
Assuming a percentage is a percentage everywhere. Tipping norms differ enormously between countries and even between types of venue in the same city. The arithmetic here is universal; the expected rate is not.
Forgetting that the headline figure is per person. Reading the large number as the total is an easy mistake when you are in a hurry. The label above it says which it is.