How it works
Enter the bill, choose a tip percentage, and optionally the number of people sharing. The tip is the bill multiplied by the percentage, rounded to the cent, and the total is the bill plus that rounded tip, so the three figures always add up. For example, a bill of 60 with a 20% tip is 72.00 in total, or 24.00 each for three people.
Splitting and rounding
When a total does not divide evenly, each person's share is rounded to the cent and the calculator tells you the difference instead of hiding it. Splitting 50 three ways gives 16.67 each, which adds up to 50.01, or 0.01 more than the total; one person can simply pay a cent less.
No default percentage
Tipping customs differ widely from country to country: in some places a tip of 15 to 20 percent is expected, in others service is already included in the bill, and in some tipping is unusual. For that reason no percentage is pre-selected. The preset buttons are shortcuts only, and you can type any percentage from 0 to 100.
Tax
The calculator applies the tip to the amount you enter. Whether to tip on the amount before or after tax is a matter of local custom; enter whichever amount you want the tip calculated on.