Grams per liter to grams per gallon (UK) conversion calculator shown above calculates how many grams per gallon (UK) are in 'X' grams per liter (where 'X' is the number of grams per liter to convert to grams per gallon (UK)). In order to convert a value from grams per liter to grams per gallon (UK) (from g/L to g/gal) simply type the number of g/L to be converted to g/gal and then click on the 'convert' button.