How many bottles of water equal 1 liter?

Depends on the size of the water bottle.

There is somewhere between 33 and 35 ounces to a liter, depending on if you're using US or Imperial fluid ounces. A typical disposable water bottle is approx. 18 ounces (the Gatorade bottle I have is 20 ounces), so it would be just barely under two water bottles - about 1.9 water bottles to a liter.