Enter the bill, pick a tip percentage, and split it across the table. Round the tip or the total up so nobody fumbles for change.
On a $50.00 bill at 18%
$9.00tip
In the U.S., 15–20% is the standard range for good restaurant service, with 20% for excellent service and 10–15% for modest or buffet service. Tip on the pre-tax amount if you want to be precise, though most people simply tip on the total — the difference is small.
Quick mental math: move the decimal point one place left (that's 10%), then add half of that for 15% or double it for 20%. On a $43 bill: 10% is $4.30, so 15% is about $6.45 and 20% is about $8.60.
Outside the U.S., tipping customs vary — many countries include service in the bill or expect only small change. When splitting, remember the tip is shared fairly only if everyone's share of the bill is similar; otherwise agree on who tips what.