PKCALC, an interactive computer program written in BASIC, facilitates: initial statistical analysis of multisubject data sets, pharmacokinetic analysis of experimental data, transfer of data between commercially available electronic spread-sheets (e.g., LOTUS 123) and the pharmacokinetic programs ESTRIP and PCNONLIN, and rapid preparation of graphs of data. Concentration versus time data can be entered into the program manually, from a data interchange format (DIF) file, or from a data file previously generated by PKCALC. The program has a main menu listing nine options. These include, but are not limited to, setting up a data file which can subsequently be read by PCNONLIN, chaining to a copy of ESTRIP augmented to read PKCALC data files, stripping curves manually, and utilizing the CRT and a line printer to graph polyexponential equations and/or subject data on linear or semilogarithmic axes. PKCALC runs on the IBM PC, IBM XT, IBM AT, and COMPAQ personal computers.