Kilograms is a measurement of weight. So depending on what substance you are weighing a gallon of it will be different weights. Kiloliters is a little bit high of a measurement to compare to gallons, you might want to stick with liters. A gallon is 3.785 liters.. Or .003875 kiloliters.
If you really need a number for kilograms in a gallon, an imperial gallon is 10lbs. Of water, or 4.535 kg.
If you really need a number for kilograms in a gallon, an imperial gallon is 10lbs. Of water, or 4.535 kg.