Employing a suitable scaling rule in gas–liquid flow can produce dynamically comparable results, which helps in the development of flow models applicable to a wide range of flow conditions and reduces the carbon footprint; however, matching all dimensionless numbers in gas–liquid flow is a challenge. This study uses a computational fluid dynamics approach to identify key dimensionless numbers that can produce dimensionally equivalent results under a variety of flow conditions in the vertical Venturi of varied sizes. The performance of the scaling rule is evaluated and validated based on experimental measurements in terms of the phase fraction, the Venturi dimensionless pressure drop, and the two-phase discharge coefficient.