One common question we receive is what is this number that is displayed next to the note? (for example what is "2" in "E2"?)

This number follows the scientific pitch notation standard and it indicates the octave of the note.
For example the frequency of E2 is 82.2 Hz while the frequency of E3 is 164.4Hz. Note that if the wrong octave is chosen this might cause the string to snap if too much tension is applied.

If you are creating a custom tuning one way to find the correct octave number is to check the frequency of a string (that appears on the top right corner of the note picker screen)

Make sure that the frequency on this string is closest to that of the standard tuning of your instrument. The frequencies of the standard tuning of a 6 string guitar are:
E2: 82.2Hz
A2: 110Hz
D3: 146.5Hz
G3: 196Hz
B3: 246.4Hz
E4: 328.9Hz

If you want to see the notes for some common alternate tunings check this article.

In case this is still confusing, reach out to us at and we will be happy to give you the exact octave for any tuning you like.