How to Calculate a Tip and Split a Bill

Tipping customs vary widely by country, but knowing the maths behind tips and bill-splitting means you can handle any situation at the table.

How to Calculate a Tip

Tip amount = Bill total × (Tip % ÷ 100)
Grand total = Bill total + Tip amount

Example: £85 bill, 15% tip:

Tip    = 85 × 0.15 = £12.75
Total  = 85 + 12.75 = £97.75

Tipping Norms by Country

Country	Restaurants	Notes
USA / Canada	15–20%	Expected; below 15% signals poor service
UK	10–15%	Often optional; check if service charge is already included
Australia	0–10%	Tipping not expected; labour laws provide minimum wages
Germany	Round up or ~5–10%	Pay in cash to the server directly
Japan	None	Tipping is considered rude in most contexts
India	5–10%	Common in restaurants; tips often cash
UAE	10–15%	Appreciated; service charge often already added

Always check the bill for a service charge — if one is included, a tip on top is optional.

Splitting Evenly

When splitting equally:

Per person = (Bill + Tip) ÷ Number of people

Example: £97.75 total split between 4 people = £24.44 each

Splitting by What Each Person Ordered

When people order very different amounts, an even split feels unfair. Calculate each person's share:

1. Add up each person's items.
2. Calculate the tip for each share proportionally:

   Person's tip = (Person's subtotal ÷ Bill total) × Total tip
   

3. Each person pays their subtotal + their proportional tip.

Example: Alice £30, Bob £55 — total £85, 15% tip (£12.75):

• Alice: 30 + (30/85 × 12.75) = 30 + 4.50 = £34.50
• Bob: 55 + (55/85 × 12.75) = 55 + 8.25 = £63.25

Mental Maths Shortcuts

Tip %	Shortcut
10%	Move the decimal one place left
15%	Find 10%, then add half of that
20%	Find 10%, then double it
25%	Divide by 4

10% of £64 = £6.40 → 15% = £6.40 + £3.20 = £9.60

What About a Group With Alcohol and Non-Drinkers?

The fairest approach: calculate alcohol separately, split it among those who drank, then split food evenly (or by order). Use the Tip Splitter to handle any combination of diners, amounts, and tip percentages without the table arithmetic.