Project: Tip Calculator

Restaurant math is a perfect first calculator. In this project you will build a tip calculator that takes a bill amount, a tip percentage, and a number of people, then works out the tip, the total, and how much each person owes.

What You'll Build

Step 1: The Inputs

Store the three inputs in variables. Later you could read these from a user, but for now we set them directly so the result is predictable:

Step 2: Do the Math

The tip is the bill times the percentage divided by 100. The total is the bill plus the tip. The per-person amount is the total divided by the number of people:

Notice per_person has a long trail of decimals. Money should show only two, so we format it in the next step.

Step 3: Format Like Money

Use :.2f inside f-strings so every amount shows exactly two decimal places.

Build It Yourself

Produce the exact three-line receipt below using bill = 48.50, tip_percent = 18, and people = 3.

Make It Your Own

Change the bill, tip, or number of people and rerun. Try a 20% tip on a $75 bill split between 4 people:

Challenge Ideas

• Round each person's share up so the tip is never short (look up math.ceil)
• Print the tip percentage in the receipt heading
• Add a line for the bill before tip so the receipt is complete

Key Takeaways

• Break a calculation into named steps: tip, total, per_person
• / 100 turns a percentage into a fraction
• Format currency with f'${value:.2f}'
• Changing the inputs instantly changes the output, which is what makes it a tool