On a $120 bill, an 18% tip is $21.60. The total is $141.60, so four people each pay $35.40.
Tip first, then split
Tip = bill × rate ÷ 100. Here 120 × 18 ÷ 100 = $21.60. Add it to the bill to get $141.60, then divide by the number of people: $35.40 each.
Splitting the total, not the bill alone, makes sure the tip is shared too.
Choosing a rate
The same $120 bill gives $18.00 at 15%, $21.60 at 18% and $24.00 at 20%. Customs vary by country: check local practice, and whether service is already included.
Quick mental math
For 10%, move the decimal one place. Double that for 20%, or add half of it for 15%. The table shows tips by bill size at three common rates.
| Bill | Tip at 15% | Tip at 18% | Tip at 20% |
|---|---|---|---|
| $40 | $6.00 | $7.20 | $8.00 |
| $80 | $12.00 | $14.40 | $16.00 |
| $120 | $18.00 | $21.60 | $24.00 |
| $200 | $30.00 | $36.00 | $40.00 |
FAQ
Should the tip be calculated before or after tax?+
Many people tip on the pre-tax amount; others tip on the total. Pick one and use the same base for the whole table.
How do I split a bill when people ordered different amounts?+
Work out each person's share of the bill, then apply the same tip rate to each share.