What Is This Calculator?
The What Percentage Did I Tip Calculator works backwards from a tip you already left. Instead of telling you how much to tip, it tells you what percentage of the bill your tip actually represented. This is handy when you handed over a round number, split a check, or want to check whether a suggested tip on a receipt matches the percentage you intended.
How to Use It
Enter two values: the original bill amount (before tip) and the tip amount you added. The calculator divides the tip by the bill, multiplies by 100, and shows the resulting percentage along with the total amount you paid.
The Formula Explained
The math is a simple percentage relationship:
$$\text{Tip \%} = \frac{\text{Tip}}{\text{Bill}} \times 100$$
The bill is the base (the whole), and the tip is the part you compare against it. Multiplying by 100 converts the decimal fraction into a percentage. Tipping conventions in the United States are typically 15%–20% of the pre-tax bill, so this tool helps you see where your tip falls.
Worked Example
Suppose your bill was $50.00 and you left a $9.00 tip. $$\text{Tip \%} = \frac{9}{50} \times 100 = 0.18 \times 100 = 18\%$$ You paid a total of \(\$50 + \$9 = \$59.00\). So you tipped a generous 18%.
FAQ
Should I use the bill before or after tax? Tip percentage is usually calculated on the pre-tax subtotal. If you only have the after-tax total, the resulting percentage will be slightly lower than the conventional pre-tax figure.
What is a standard tip percentage? In the U.S., 15% is considered standard, 18%–20% is good, and 20%+ is excellent for sit-down service.
What if my bill is $0? The percentage is undefined when there is no bill, so the calculator returns 0% in that case.
