Barrels (oil) to gills (UK) conversion calculator above calculates how many gills (UK) are in 'X' barrels (oil) (where 'X' is the number of barrels (oil) to convert to gills (UK)). In order to convert a value from barrels (oil) to gills (UK) just type the number of bbl to be converted to gills (UK) and then click on the 'convert' button.