LPG Gas Measured by meter in m3 but billed in litres how do they convert m3 back to litres?

1 cc = 1 ml  1,000 cc = 1 litre  1 meter = 100 centimeters.  1 m^3 =100cm x100cm x100cm or 1,000,000cc.  Divided by 1,000cc/ litre = 1,000 litre/m^3.  So multiply m^3 x 1,000 to convert to litres.