Working out a tip shouldn't need a debate at the table. Whether you want a quick mental estimate or an exact split across a group, the maths is simple once you know the shortcuts — and knowing roughly what to tip in different situations saves the awkward guesswork.
This guide covers how to calculate a tip fast, how much to tip in common situations, and how to split the bill fairly.
What you need
- ✓The bill total.
- ✓A tip percentage you're happy with.
- ✓The number of people, if you're splitting it.
Step-by-step
- 1
Do the quick mental version
Find 10% by moving the decimal one place left (a $60 bill → $6). Then for 20%, double it ($12); for 15%, take 10% plus half of it ($6 + $3 = $9). This gets you a good tip in seconds without a calculator.
- 2
Or calculate it exactly
Multiply the bill by the tip as a decimal: $60 × 0.18 = $10.80 tip, for a $70.80 total. A tip calculator does this instantly and avoids rounding errors on odd amounts.
- 3
Decide the percentage for the situation
In tipping cultures, sit-down restaurant service is commonly 15–20%, with 20% for good service; smaller tips or rounding up suit cafes, bars and takeaways. Norms vary a lot by country — check local custom when travelling.
- 4
Tip on the pre-tax amount (if you like)
Whether to tip on the pre-tax or post-tax total is your call — pre-tax is technically the service amount. Decide once and be consistent so the maths stays simple.
- 5
Split the bill fairly
For an even split, add the tip to the bill, then divide by the number of people ($70.80 ÷ 3 = $23.60 each). Round each share up slightly so the tip is fully covered when everyone pays.
Examples
- A $60 bill at 20%: 10% is $6, double it to $12 tip, total $72 — done in your head.
- A $84.50 bill split three ways with an 18% tip works out to about $33.24 each — exact, via the calculator.
Tips
- →Learn the 10% trick: move the decimal, then scale to 15% or 20%.
- →Round the total up to a tidy number to make paying and splitting easy.
- →Check local tipping norms when travelling — they differ widely.
- →Agree pre-tax vs post-tax once so there's no table debate.
- →Round each person's share up slightly so the tip is fully covered.
Common mistakes
- Fumbling the mental maths. Anchor on 10% (move the decimal), then scale up to your percentage.
- Under-splitting the tip. Add the tip first, then divide, and round each share up a touch.
- Assuming one norm everywhere. Tipping customs vary by country — check before you travel.
- Debating pre vs post tax. Pick one basis and be consistent to keep it simple.
Conclusion
Calculating a tip is quick once you anchor on 10% and scale to your percentage — or let a tip calculator handle the exact figure and split. Know the rough norm for the situation, agree the pre- or post-tax basis, and round shares up so the tip is always covered.