A method for determining a volume of beverage, preferably being a carbonated beverage such as beer or soft drink, being included in a collapsible beverage container, said method comprising providing a beverage dispensing system, said beverage dispensing system including: a pressure chamber in which said collapsible container is included, said pressure chamber defining an inner volume being equal to the sum of said volume of beverage and a residual gas volume, a pressurization system for supplying a volume of gas of atmospheric pressure from said outside of said pressure chamber to said residual gas volume, and a pressure sensor for detecting a low pressure value p low and a high pressure value p high, respectively, in said inner volume, said high pressure value being higher than said low pressure value, said method further comprising the steps of: supplying said volume of gas to a residual gas volume by using said pressurization system in response to detecting said low pressure value of said inner volume and raising said pressure in said inner volume from said low pressure value to said high pressure value, determining said volume of gas supplied by said pressurization system from the outside of said pressure chamber to said residual gas volume in between detecting said low pressure value in said inner volume and detecting said high pressure value in said inner volume, and establishing a measure of said volume of beverage included in said collapsible beverage container, said measure being based on said gas volume, said inner volume, said low pressure value and said high pressure value, characterised in that said low pressure value being higher than atmospheric pressure, and that the volume of beverage V bev remaining in the beverage container is calculated according to V bev = V in − n op ⋅ V spec p high − p low wherein V in is the volume of the inner volume, V spec of atmospheric pressure introduced by each operational cycle, n op is the number of operation cycles performed between reaching p low and p high in the pressure chamber. a pressure chamber in which said collapsible container is included, said pressure chamber defining an inner volume being equal to the sum of said volume of beverage and a residual gas volume, a pressurization system for supplying a volume of gas of atmospheric pressure from said outside of said pressure chamber to said residual gas volume, and a pressure sensor for detecting a low pressure value p low and a high pressure value p high, respectively, in said inner volume, said high pressure value being higher than said low pressure value, supplying said volume of gas to a residual gas volume by using said pressurization system in response to detecting said low pressure value of said inner volume and raising said pressure in said inner volume from said low pressure value to said high pressure value, determining said volume of gas supplied by said pressurization system from the outside of said pressure chamber to said residual gas volume in between detecting said low pressure value in said inner volume and detecting said high pressure value in said inner volume, and establishing a measure of said volume of beverage included in said collapsible beverage container, said measure being based on said gas volume, said inner volume, said low pressure value and said high pressure value, characterised in that said low pressure value being higher than atmospheric pressure, and that the volume of beverage V bev remaining in the beverage container is calculated according to V bev = V in − n op ⋅ V spec p high − p low wherein V in is the volume of the inner volume, V spec of atmospheric pressure introduced by each operational cycle, n op is the number of operation cycles performed between reaching p low and p high in the pressure chamber.