A correlation is developed for the volumetric gas-liquid mass transfer coefficient (k(L)a) in stirred-tank reactors (STRs) using results from the literature. The volumetric mass transfer coefficient is correlated on the basis of the relative dispersion parameter (N/N-CD) for similar impeller hydrodynamics and operating regimes. Using a bench-top STR of diameter T = 0.211 m, gas-liquid mass transfer data are also obtained and found to follow the proposed correlation when the appropriate hydrodynamic conditions are satisfied. A STR scale-up technique from bench-scale (T = 0.211 m and D/T = 0.35) to industrial-scale (up to T = 2.7 m) is proposed using a normalized hydrodynamic flow regime map and shown to be useful in understanding the range of operational conditions for the successful scale-up of STRs.