How to Calculate a Tip (15%, 18%, 20%)
Updated June 2026
Split the bill and tip.
Figuring out a tip in your head is easy once you know the 10% trick. Here's how — plus a reference table and how to split it.
The formula
Tip = Bill × (Tip % ÷ 100)
Total = Bill + Tip. To split: divide the total by the number of people.
The 10% mental trick
Move the decimal one place left to get 10% of the bill. Then:
- 15% = 10% + half of 10%
- 20% = 10% doubled
On a $50 bill: 10% is $5, so 15% is $7.50 and 20% is $10.
Quick reference
| Bill | 15% | 18% | 20% |
|---|---|---|---|
| $25 | $3.75 | $4.50 | $5.00 |
| $50 | $7.50 | $9.00 | $10.00 |
| $100 | $15.00 | $18.00 | $20.00 |
How much should you tip?
In the US, 15–20% is standard for sit-down service, with 20% for good service. For takeout, tipping is optional. The tool below also splits the total evenly across your group.
Split the bill and tip.
Frequently asked questions
Do I tip on the pre-tax or post-tax amount?
Either is acceptable; many people tip on the pre-tax subtotal. The difference is small for most bills.
How do I split a bill with a tip?
Add the tip to the bill, then divide the total by the number of people. The calculator does both at once.