Write out the notes of the chord. For instance, if you have a C minor (Cm) chord, you would write the notes C, Eb and G.
Choose another chord to which you will convert the notes. For instance, you might want to convert to an Fm chord.
Count the half steps between the root note (the note for which the chord is named) of the original chord and the new chord. In this example, you would count half steps between C and F. There are five half steps between these two notes (C#/Db, D, D#/Eb, E, F).
Increase or decrease the other notes by the same number of half steps. In this example, you went up five half steps from C to F. Therefore, you would count up five half steps from the next note (Eb) to get the note Ab. The last note was G, so you would count up five half steps from G to get a C note. This creates the Fm chord by combining the notes F, Ab and C.