Abstract: By comparing and analyzing the distributions of Mindlin stress coefficient and Boussinesq stress coefficient under the corner of rectangular uniformly-distributed load with different buried depths and length-width ratio, the relationship between Boussinesq and Mindlin solutions is established statistically. The experiential coefficient for settlement calculation is obtained by back analysis on the measured settlement results of about sixties buildings in Beijing. An unified formula for settlement calculation characterized by a coefficient of correction for depth is proposed finally. The formula is suitable for the settlement calculation of both natural foundations and pile foundations.