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