I am a Chinese National visiting the U.S. on a B2 tourist visa. If I stay in the U.S. for 180 days. How long must I leave the country for until I can return?
There is no hard-and-fast rule setting time limits on tourist entries to the United States.
The informal rule of thumb is that you should spend in your home country at least as much time as you spent in the US. Even if your visa is still valid, US CBP will deny you entry if the officer thinks you're actually living in the US by repeated tourist entries.