A method for determining the flow rates of a multi-component mixture in a pipe including a gas phase and a liquid phase, the method comprising the following steps: a. the flow rates of the individual components of the multi-component mixture are measured, b. the Reynolds number of the multi-component mixture is measured separately from the flow rate measurements, and c. based on the result from step a and b, a more accurate flow-rate of the individual components of the multi-component mixture is calculated. An apparatus for performing the method is also disclosed.