Formula to convert 12.9 liters to gallons is to multiply 12.9 by 0.264172 (this is the value for 1 liter to gallon).
Convert 12.9 Liters to Gallons results
12.9 x 0.264172052 = 3.40781947596
12.9 l = 3.41 gal
To conclude the answer for 12.9 liters is three point forty one gallons