Instant gratuity math with bill splitting.
Tip = Bill × Tip% / 100. Per person = (Bill + Tip) / People.
$60 bill, 18% tip, split 2 ways → $10.80 tip, $70.80 total, $35.40 each.
Tipping norms vary widely by country and by service. In the U.S., 15–20% is standard for sit-down restaurants; adjust up for exceptional service.
Traditionally pre-tax, but many people tip on the total — either is acceptable.
10–20% or $5 minimum, weather- and distance-dependent.