Dry-kiln schedules have been developed for many wood species. However, one problem is that many, especially tropical species, have no recommended schedule. Another problem in drying tropical species is the lack of a way to group them when it is impractical to fill a kiln with a single species. This report investigates the possibility of estimating kiln schedules and grouping species for drying using basic specific gravity as the primary variable for prediction and grouping. In this study, kiln schedules were estimated by establishing least squares relationships between schedule parameters and basic specific gravity. These relationships were then applied to estimate schedules for 3,237 species from Africa, Asia and Oceana, and Latin America. Nine drying groups were established, based on intervals of specific gravity where drying times were similar, with the appropriate schedule applied to all members of the group.