Tipping in the United States

18-25%

18-25% of the pre-tax bill at sit-down restaurants. Older guides still quote 15-20%; 15% now reads as the low end.

Sources: [1] [2] [3]

Don't double tip

Large groups often get an automatic service charge on the bill. If it's there, you don't tip again.

Sources: [2] [3]

10-15%

Tip taxi drivers, typically 10-15% of the fare.

Sources: [1] [3]

Yes

Leave cash for housekeeping (usually on the last day) and tip porters per bag.

Sources: [2] [3]

$5-20 pp/day

Tip tour guides, roughly $5-20 per person per day depending on the tour.

Sources: [2] [3]