you might find that there are different voicings of the chord you want to play that better fit the shape of your fingers. a voicing is when u keep the notes the same but change were they are played. in a normall majour chord there are three notes (although they may be several octaves of the same note). an example of this is open G and a g chord made from a barre chord at the third fret have different voicings, and therefore shapes, but are the same chord.