Music Calculator

In this part, you can select which note you would like to know the duration of (at the tempo selected in the "Tempo" section). The length is (obviously?) affected by whether or not the note is dotted and whether or not it is in a tuplet and of course, what sort of tuplet it is in.
The "dot" button switches the dot on or off, and the icon will change accordingly.

This is where you set the tempo. You can either chose a "standard" musical tempo by name, or type a precise tempo in the text box. The two are interactive. The text entry field, like all the text fields on the calculator can be validated by either clicking outside the field or pressing "Tab" (⇥), "Return" (↩︎) or "Enter" (⌅).
Tempo is usually given to the quarter note (which is the calculator's default), but can occasionally be given to the eighth note or to the half note, and you can choose these as you wish.

Here you can choose the number of measures in your piece, if you need an estimate of it's total duration. Obviously, if your piece contains tempo changes, these will have to be taken into account and dealt with separately. The durationn is of course also tributatary of the time signature, which is why it figures here as well.

You can also set values for tuplets, which will change the note duration. You can choose any variant you wish amongst the proposed more common musical values, and the "OFF/ON" switch applies the tuplet to the duration or not.

This is a summary of the calculations made using all your settings above. You can see these results change in realtime, as you change the settings.