How the tip is calculated
Three steps, and the calculator shows all of them. The tip is a percentage of the bill, the total is the bill plus that tip, and each person's share is the total divided by the number of people.
tip = bill × (percentage ÷ 100)
total = bill + tip
per person = total ÷ number of people
With round up switched on, each person's share is rounded up to the next whole unit first, then the total and tip are recalculated from that figure — so the numbers on the table always add up to what is actually being paid.
Tip percentages are conventionally applied to the pre-tax subtotal, since tax is not part of the service. Applying the percentage to the post-tax total is also common and simply produces a slightly larger tip.
Worked example
Four people share a $120 dinner bill and want to leave 18%.
- Bill
- $120.00
- Tip rate
- 18%
- Tip
- 120 × 0.18 = $21.60
- Total
- 120 + 21.60 = $141.60
- Split 4 ways
- 141.60 ÷ 4 = $35.40
Each person pays $35.40, of which $5.40 is the tip.
Common questions
How much should I tip at a restaurant?
In the United States, 18–20% of the pre-tax bill is the common range for table service. 15% reads as the low end, and 25% is generally reserved for exceptional service. Counter service and takeaway attract 0–10%, or nothing at all. These norms are specific to the US — most of the world tips considerably less, or not at all.
Do I tip on the pre-tax or post-tax amount?
Convention is to tip on the pre-tax subtotal, on the reasoning that sales tax is not part of the service you received. Tipping on the post-tax total is also widespread and simply results in a slightly larger tip — on a $120 bill with 9% tax, the difference is about $1.94 at 18%.
How do I split a bill when people ordered different amounts?
Work out each person's share of the subtotal first, then apply the same tip percentage to each share, so everyone tips in proportion to what they ordered. This calculator splits evenly, which is simpler and is what most groups actually do.
Is tipping expected in Australia?
No. Australian hospitality staff are paid an award wage rather than a tipped minimum, so a tip is genuinely optional. Rounding up the bill, or leaving 5–10% for exceptional service, is considered generous. Switch the locale in the header to see Australian defaults.
Tipping conventions described on this page reflect general custom and are provided for guidance only. SwiftSums shows every formula it uses so you can check the arithmetic yourself.