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