Fluid ounces (UK) to gallons (UK) conversion calculator shown above calculates how many gallons (UK) are in 'X' fluid ounces (UK) (where 'X' is the number of fluid ounces (UK) to convert to gallons (UK)). In order to convert a value from fluid ounces (UK) to gallons (UK) (from fl oz to gal) type the number of fl oz to be converted to gal and then click on the 'convert' button.