Abstract: The relationship between the settling time of a sphere in a fluid and other six variables through dimensionless products was experimentally studied. The experimental design and the testing for attaining component equations were carried out strictly following the principles for combination of a π-equation. The experimental results revealed that the prediction at the points on the curve of every component equation are highly precise, provided that the regression equation has a high correlation coefficient and the precision of the prediction declines along with the deviation of the point from the component equation’s curve.