We have formulated a combining rule for solid-liquid adhesion and intermolecular potentials using macroscopic adhesion data. The combining rule is applied successfully to determine macroscopic solid-liquid adhesion and to calculate adhesion patterns using molecular theory. We found that the results determined from our combining rule are better than those by the 9:3, Steele's, and 12:6 combining rules in terms of scatters and details. Our results suggest that rnacroscopic data front careful contact angle and adhesion findings can be used to infer relationships of unlike solid-fluid interactions at a molecular level.