Interval Finder
Find the interval between any two notes.
Tap any key to move the second note. Swap turns the pair around; New pair starts from scratch.
On the staff
Interval anatomy
| Property | Value |
|---|---|
| Interval | Major 3rd |
| Symbol | M3 |
| Semitones | 4 |
| Whole tones | 2 |
| Scale degrees | 1 → 3 |
| Inversion | Minor 6th |
| Inversion symbol | m6 |
| Consonance | imperfect consonance |
| Enharmonic equivalent | Diminished 4th (d4) |
How this interval is built
C4 to E4 spans three letter names, C-D-E, making it a 3rd. It contains 4 semitones, which makes that 3rd major.
Where you will find this interval
Chords built on C that stack major 3rd above the root:
Every interval inside an octave
| Interval | Symbol | Semitones | Whole tones | From C | Consonance |
|---|---|---|---|---|---|
| P1 | 0 | 0 | C to C | perfect consonance | |
| m2 | 1 | ½ | C to D♭ | dissonance | |
| M2 | 2 | 1 | C to D | dissonance | |
| m3 | 3 | 1½ | C to E♭ | imperfect consonance | |
| M3 | 4 | 2 | C to E | imperfect consonance | |
| P4 | 5 | 2½ | C to F | imperfect consonance | |
| A4 | 6 | 3 | C to F♯ | ambiguous | |
| P5 | 7 | 3½ | C to G | perfect consonance | |
| m6 | 8 | 4 | C to A♭ | imperfect consonance | |
| M6 | 9 | 4½ | C to A | imperfect consonance | |
| m7 | 10 | 5 | C to B♭ | dissonance | |
| M7 | 11 | 5½ | C to B | dissonance | |
| P8 | 12 | 6 | C to C | perfect consonance |
Pick any row to load it into the finder. The tritone is listed as the augmented 4th; spelled the other way, the same six semitones are a diminished 5th.
How intervals work
An interval is the distance between two notes, and it is measured twice. The first measurement is the letters. Count the letter names from the lower note to the upper one, including both ends: C up to E covers C, D and E, three letters, so the interval is a third. That count gives the interval its number, and it comes from how the notes are written rather than from how they sound.
The second measurement is the semitones, the half steps between the two keys. A third containing four semitones is major; a third containing three is minor. Put the two measurements together and you have the full name. This is also why enharmonic spelling changes the answer: C up to D sharp and C up to E flat are the same key and the same three semitones, but the first spans two letters and the second spans three, so one is an augmented second and the other is a minor third.
Unisons, fourths, fifths and octaves are perfect intervals. They have no major or minor form: a semitone wider makes them augmented, a semitone narrower makes them diminished. Seconds, thirds, sixths and sevenths are the major and minor family, where the first semitone down turns major into minor and only the second reaches diminished. Every interval also has an inversion, found by moving the lower note up an octave. The two numbers add to nine and the two semitone counts add to twelve, so a major third inverts to a minor sixth and a perfect fifth inverts to a perfect fourth.
Past an octave, intervals are called compound. A ninth is a second plus an octave and a tenth is a third plus an octave, which is where chord extensions get their numbers. For the twelve semitone distances inside an octave, see the table above, or read the full page on any of them starting from the perfect fifth, the major third, or the tritone.
Frequently asked questions
What is a musical interval?
An interval is the distance between two notes, measured two ways at once. Its NUMBER comes from how many letter names the two notes span, counting both ends: C to E covers C, D and E, so it is a third. Its QUALITY comes from how many semitones it actually contains: a third of four semitones is major, and one of three semitones is minor. You need both numbers, which is why an interval is named with a word and a digit rather than a digit alone.
Why are C to D sharp and C to E flat different intervals?
They are the same two keys on the piano and the same three semitones, but they are written differently, and the letters decide the number. C to D sharp spans two letter names, C and D, so it is some kind of second; three semitones makes that second augmented. C to E flat spans three letter names, C, D and E, so it is some kind of third; three semitones makes that third minor. Same sound, different spelling, different name. This is the one thing a tool that works from pitch alone cannot tell you.
What is the difference between perfect and major or minor intervals?
Unisons, fourths, fifths and octaves are called perfect. They have no major or minor form: widen one by a semitone and it is augmented, narrow it and it is diminished. Seconds, thirds, sixths and sevenths come in major and minor. Narrow a major one by a semitone and it becomes minor, and only a second semitone makes it diminished. That asymmetry is why a fifth lowered by a semitone is a diminished fifth while a third lowered by a semitone is only a minor third.
What is a compound interval?
Any interval wider than an octave. A ninth is a second plus an octave, a tenth is a third plus an octave, and so on. Compound intervals keep the character of the simple interval inside them, which is why chord extensions are named 9, 11 and 13 rather than 2, 4 and 6: the number says the note is voiced above the octave.
How do I invert an interval?
Move the lower note up an octave, or the upper note down one. The two numbers always add up to nine, so a third inverts to a sixth and a fifth inverts to a fourth. The qualities mirror: major becomes minor, augmented becomes diminished, and perfect stays perfect. The semitones always add up to twelve.
Which intervals are consonant?
The unison, fifth and octave are perfect consonances. Thirds and sixths, major or minor, are imperfect consonances, which is why they carry most harmony. Seconds and sevenths are dissonances. The tritone, six semitones, sits on its own: it is neither, and its character comes from where it resolves rather than from how it sounds standing still.