The volumetric mass transfer coefficient (k(L)a) plays a crucial role in industrial design in the case of the process controlled by gas-liquid mass transfer. Prediction of k(L)a is nowadays mostly based on literature correlations. Our research goal is to establish suitable k(L)a correlations for different types of devices that would be based on the experimental dataset. This article aims at the description of one universal correlation that would be viable for mechanically agitated gas-liquid contactors and also for pneumatically agitated gas-liquid contactors such as airlift reactor. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.