Gigabars to newtons per square millimeter conversion calculator shown above calculates how many newtons per square millimeter are in 'X' gigabars (where 'X' is the number of gigabars to convert to newtons per square millimeter). In order to convert a value from gigabars to newtons per square millimeter (from Gbar to N/mm²) simply type the number of Gbar to be converted to N/mm² and then click on the 'convert' button.