BIOPAK is a menu-driven package of computer programs for IBM-compatible personal computers that calculates the biomass, area, height, length, or volume of plant components (leaves, branches, stem, crown, and roots). The routines were written in FoxPro, Fortran, and C. BIOPAK was created to facilitate linking of a diverse array of vegetation datasets with the appropriate subset of available equations for estimating plant components, such as biomass and leaf area. BIOPAK produces reports that are formatted for people and files that are compatible with other software. Other reports document the design of a computation run and the equations used. The guide provides information in installation, reference, and tutorials.