PQcalc

PQcalc is an online calculator for sciences learners. You can try it out here. For beginning students, this version gives a bit more feedback. To learn how to use the tool, click on the help button below the input box of PQcalc (this will fill the input box with some command, which you can then try by hitting the go button). For a quick tour of the user interface, watch the video. For a more detailed overview of the capabilities, take a look at the manual. The source code is available at github.