To determine how many milliliters are in 1 gallon, we can use the fact that 1 gallon = 4 quarts.
Given that: 1 quart = 946.35 mL
We can calculate the milliliters in 1 gallon as follows:
1 gallon = 4 quarts × 946.35 mL/quart
Calculating that gives: 1 gallon = 4 × 946.35 mL = 3785.4 mL
So, the answer is 3785.4 mL.