How to Split a Bill and Calculate a Tip
Tipping arithmetic is simple enough to do in your head, and splitting a bill is where it gets socially complicated. The Tip Calculator handles the tip, the total and the per-person split.
Ten per cent is the only thing to memorise
Move the decimal point one place left. A bill of 86.40 has a 10 per cent tip of 8.64.
Everything else builds from that. 15 per cent is 10 plus half of 10 - 8.64 plus 4.32, so about 12.96. 20 per cent is 10 doubled, 17.28. 18 per cent is 20 minus a tenth of 20, around 15.55. 12.5 per cent is 10 plus a quarter of 10.
Rounding to a convenient total afterwards is normal and nobody minds.
Pre-tax or post-tax
Convention says the tip is calculated on the pre-tax amount, since tax is not a service anyone provided. In practice most people tip on the total because it is the number printed largest, and the difference on a moderate bill is small.
What is worth watching is a card machine or app suggesting percentages calculated on the post-tax total, and sometimes on a total that already includes a service charge - at which point you are tipping on the tip.
Check for a service charge before adding anything. Many restaurants, particularly for larger groups, add 10 to 15 per cent automatically. Adding a tip on top is a double payment, and it is easy to miss on a long bill.
What actually makes splitting awkward
Not the division. Two things.
Unequal orders. Splitting a bill evenly when one person had a starter, three drinks and dessert and another had a salad and tap water is a transfer, not a split. The fair version is itemised, and the socially easy version is even, and which one applies depends on the group rather than on arithmetic.
A reasonable middle ground that works well: split the food evenly and settle drinks separately, since drinks are usually where the variation is.
Rounding. A bill of 100 across three people is 33.33 each, which leaves a cent. Someone rounds up. On larger numbers it is worth one person covering the remainder rather than anyone transferring pennies.
Tipping norms vary enormously
Worth knowing rather than assuming. In the United States, tipping is a substantial part of service pay and 18 to 20 per cent is the current expectation in restaurants. In much of Europe, service is included and rounding up or 5 to 10 per cent is generous. In Japan tipping is not customary and can cause confusion.
Travelling, the honest answer is to look up the local norm for the country rather than exporting your own.
Common questions
How do I split by percentage rather than evenly?
Work out each person's share of the bill, then apply the same tip percentage to each share.
Who pays the tip on a split bill?
Everyone, in proportion. Calculating the total with tip and then dividing handles it automatically.
Is tipping a delivery driver different?
Usually a flat amount rather than a percentage, since the work does not scale with the order value.
Got a bill to split?