How to Calculate Tips: All Methods, Bill Splitting, and International Etiquette

Whether splitting a restaurant bill, rewarding great service, or working out what a service charge means, tip calculations come up constantly. Here are all the methods in one place.

Basic Tip Calculation

Tip = Bill × Tip percentage
Total = Bill + Tip

Example: £65 bill, 15% tip:

Tip = £65 × 0.15 = £9.75
Total = £65 + £9.75 = £74.75

Mental Maths Shortcuts

For 10%: Move the decimal one place left. £65 → £6.50

For 15%: Find 10%, halve it, add:

• 10% of £65 = £6.50
• 5% of £65 = £3.25
• 15% = £6.50 + £3.25 = £9.75

For 20%: Double the 10% figure. £6.50 × 2 = £13.00

For any %: Multiply by (% ÷ 100).

Splitting the Bill

Equal Split

Each person pays = (Bill + Tip) ÷ Number of people

Example: £120 bill, 15% tip, 4 people:

Tip = £18
Total = £138
Each pays = £138 ÷ 4 = £34.50

Itemised Split with Tip

Each person pays their items plus their proportional share of the tip:

Person's share = (Person's items ÷ Total bill) × (Bill + Tip)

Example: Alice had £40 of a £120 bill, 15% tip:

Alice's proportion = 40 ÷ 120 = 33.3%
Alice pays = 33.3% × £138 = £46

Service Charge vs Tip

Many UK restaurants add a discretionary service charge (usually 10–12.5%) to your bill automatically:

• You are legally entitled to refuse it if service was poor
• Ask whether it goes fully to staff — in law, it should (as of October 2024 under the Employment (Allocation of Tips) Act)
• If you pay the service charge, you don't need to tip additionally

Tipping Norms by Country

Reverse Tip Calculation

Working out the original bill when only the total is shown:

Original bill = Total ÷ (1 + tip rate)

Example: Total paid was £74.75, tip was 15%:

Original = £74.75 ÷ 1.15 = £65.00