Yamamoto's equation (Yamamoto, 1961) was modified to estimate the vortex profiles in baffled agitated vessels by assuming that the power input varied with the radius of the cylindrically rotating zone under the baffled conditions. The equation obtained is a function of agitator dimensions, baffle type and operating conditions. Under industrial conditions (b/D < 0.16, b: height of impeller blade, D: vessel diameter), the radius of the cylindrically rotating zone calculated in this work agrees with Kamei's experimental data (Kamei et al., 1999) measured in a baffled agitated vessel with a flat paddle. The vortex profile in a commercial agitated vessel can be calculated by the proposed modification of Yamamoto's equation.