Enter the bill, choose a tip percentage, and set how many people are paying. The calculator shows the tip, the total and the amount each person owes, and can round the per-person figure to a sensible number so nobody is counting out small change.
Rounding each person's share up is the fastest way to settle a table, but it quietly changes the tip. The calculator recomputes the tip from the rounded per-person figure so the percentage shown is the one actually being paid, not the one you asked for.
Conventions vary more than most travel advice admits. The United States expects 15-20% for table service and staff wages assume it. Much of continental Europe includes service, and rounding up or leaving 5-10% is generous. In Japan and South Korea tipping can cause confusion or offence. Check locally rather than exporting a habit.
Tipping on the pre-tax subtotal is the common convention in the United States, though many people simply tip on the full total for speed. On a typical bill the difference is small; this calculator tips on whatever figure you enter.
In the United States, 15-20% is standard for table service. In much of Europe service is included and rounding up is enough. In Japan tipping is generally not expected. Local convention matters more than any single number.
Steuervergleich Kanton Zürich — Gemeindesteuern vergleichen (Deutsch)