A gallon contains 128 fluid ounces. The number of water bottles that make up a gallon depends on the size of the bottle:
- For a standard 16.9-ounce (500 ml) water bottle, about 7.57 to 8 bottles equal one gallon
- For 24-ounce bottles, about 5 bottles make a gallon
- For 32-ounce bottles, about 4 bottles make a gallon
- For 40-ounce bottles, about 3 bottles make a gallon
In summary, if you are using the common 16.9-ounce bottle size, roughly 7.5 to 8 bottles of water make one gallon. The slight variation comes from the exact conversion between ounces and liters, but 8 bottles is a practical estimate
