Interval Calculator
Measure the interval between two notes, or find the note a given interval away.
Interval
perfect fifth
- Scale degree
- 5
- Shorthand
- P5
- Semitones
- 7
An interval has a number and a quality, and semitones alone cannot tell you either. C to F sharp and C to G flat both span six semitones; the first is an augmented fourth and the second a diminished fifth, and which one you have changes how it is written and where it wants to go.
How it works
The number comes from the letters, counted inclusively: C to E covers C, D and E, so it is a third whatever accidentals are on it. The quality then compares the actual distance in semitones against what that number would be in a major scale: the same distance makes it major or perfect, one semitone short makes it minor or diminished.
Transposing works the same way in reverse. The interval number decides which letter the answer lands on and the semitone count decides its accidental, which is why a major third above F flat is A flat and never G sharp.
Examples
| Case | Input | Result |
|---|---|---|
| The tritone | C up to F♯ | Augmented fourth (A4), 6 semitones |
| Counting upwards, not the short way round | E up to C | Minor sixth (m6), 8 semitones |
Frequently asked questions
Why can a fifth not be major?
Unisons, fourths, fifths and octaves are perfect rather than major or minor: they sound the same in the major and the minor scale, so there is nothing to distinguish. They can still be augmented or diminished.
What is the tritone?
Six semitones, half an octave. Written as an augmented fourth or a diminished fifth depending on the letters, and the two behave differently: an augmented fourth tends to expand outwards, a diminished fifth to contract inwards.
Intervals are always measured upwards here?
The measurement is, yes: from the first note up to the second, within an octave. The transposing mode gives you both directions at once.
Good to know
- Nothing here is a lookup table. The number comes from the letters and the quality from the semitones, so the answer follows from the spelling you gave rather than from a list of pairs somebody typed.
- These are the same intervals the transposer and the scale engine use, so a name given on this page is the name used everywhere else on the site.