Estimation of delay correlations is one of the most challenging problems in SSTA. This is because cell delay depends on a number of factors in a complex manner, which makes complex the estimation of correlations as well. In this paper, we introduce a technique to compute cell-to-cell and path-to-path delay correlations, which allows considering the effects of cell-level input/output edge, input slope and output lo ad values. Numerical results are presented to quantify its accuracy.