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