The Java software jBar consists of a graphical user interface that allows the user to customize and assemble an included script for R. The scripted R pipeline calculates means and standard errors/deviations for replicates of numerical bivariate data and generates presentations in the form of bar graphs. A two-sided Student's t test is carried out against a user-selected reference and p-values are calculated. The user can enter the data conveniently through the built-in spreadsheet and configure the R pipeline in the graphical user interface. The configured R script is written into a file and then executed. Bar graphs can be generated as static PNG, PDF, and SVG files or as interactive HTML widgets.