How many US gallons are in one liter? 1 liter = 1.06 US quarts, so 1 US quart = .943 liters and 1 US gallon = about 3.77 liters So there are about 0.265 US gallons in one liter, i.e. just over a quarter of a US …gallon. I take people as I find them, and am always willing to help if I can.