MSPeconomist

Don't forget that tipping norms depend very much on the location as well as type of establishment. In the USA, close to 20% of the pretax bill is becoming standard in full sevice restaurants in places like NYC and other big cities plus the west coast, but not so much in other USA locations. In some countries where tips are expected, the expectation is closer to 10% for decent service in most circumstances. To complicate things, where a service charge is added, a tip of up to about 10% is expected in some countries, while in other countries, one would round up or not tip at all unless the service had been extraordinary.

I try to ask/follow educated sophisticated well-traveled locals rather than trust various tipping guides, some of which seem designed to induce dumb tourists to overtip waiters.