Out of context, this sounds like an OBOE (off by one error). You typically wouldn’t count the origin: the two notes are four (semitones) away from one another. That becomes quite useful when you think about all of this as sets and, perhaps, start doing some computation with these. In context, it might simplify things for the moment. It’s just a bit strange to keep all of these in mind. The major third (so, the third note in the scale) is “five pitches” away from the root. The perfect fourth would be “six pitches” away. The perfect fifth “eight pitches away”. Major sixth “10 pitches away”. And the major seventh “12 pitches away”. Which means the octave is “13 pitches away”. Could lead to interesting confusion.