Formula to convert 20.4 liters to gallons is to multiply 20.4 by 0.264172 (this is the value for 1 liter to gallon).
Convert 20.4 Liters to Gallons results
20.4 x 0.264172052 = 5.38910986896
20.4 l = 5.39 gal
To conclude the answer for 20.4 liters is five point thirty nine gallons