How long can you stay in USA on tourist visa?

The quick answer to the question of how long a visitor can legally stay in the United States is, for most people, six months. To be more precise, once admission is deemed to be ‘fair and reasonable’, the default assumption is that the visitor is granted a six-month stay. A simple stamp in the passport without a date inscribed usually means that the passport holder has been granted a six-month period of stay. This is regardless of how long they planned to stay when they entered the United States and how long they informed the United States Customs and Border Protection (USCBP) officer. This usually applies to Canadians and travelers from other countries entering the United States with B-1 visas for business or B-2 visas for pleasure issued in their passports by US consulates abroad. Any doubts about the period of permitted stay can be resolved by visiting the US Customs and Border Protection I- 94 website.