Use note letter + accidental + octave. Valid accidentals: #, b, ##, bb, x. Example: C#4, Eb3, Fx5.
What this music interval calculator does
This calculator tells you the exact interval between two written notes, including quality (major, minor, perfect, augmented, diminished), interval number (2nd, 3rd, 10th, etc.), direction, and semitone distance. It is designed for musicians, composers, arrangers, and students who want a fast way to check interval spelling and avoid theory mistakes.
Unlike basic semitone counters, this tool also respects notation and enharmonic spelling. For example, C# to Db is not the same interval spelling as C# to C#, even though they can be the same pitch in equal temperament.
How to use it
1) Enter your first and second notes
Type notes in this format:
- Letter: A through G
- Accidental (optional): #, b, ##, bb, x
- Octave (required): integer like 3, 4, 5
Examples: C4, F#3, Bb5, Gx4, Ebb2.
2) Click “Calculate Interval”
You’ll get a result that includes interval name, direction (ascending or descending), semitones, simple interval, and equal-tempered ratio.
3) Use “Swap Notes” to reverse direction
Swapping notes is useful when checking inversions or practicing interval recognition in both directions.
Interval naming quick guide
An interval has two parts:
- Number: how far apart the letter names are (2nd, 3rd, 4th, etc.)
- Quality: perfect, major, minor, augmented, diminished
Common examples:
- C to E = Major 3rd
- C to Eb = Minor 3rd
- C to G = Perfect 5th
- C to F# = Augmented 4th
- C to Gb = Diminished 5th
Why intervals matter in real music
Chord construction
Triads and seventh chords are stacks of intervals. If you can calculate intervals quickly, you can build chords accurately in any key.
Melody writing
Melodic personality is largely interval-driven. Stepwise writing uses 2nds; dramatic writing uses wider leaps like 6ths, 7ths, and octaves.
Ear training
Strong relative pitch comes from recognizing intervals by sound and context. This calculator helps verify your answers during practice.
Arranging and orchestration
Voice leading depends on interval control. Correctly identifying compound intervals (9ths, 10ths, 13ths) makes your scores clearer and more playable.
Practice ideas
- Pick a root note and calculate every interval up to an octave.
- Write random note pairs and predict the interval before calculating.
- Practice enharmonic pairs (e.g., A# vs Bb) to strengthen notation fluency.
- Reverse each pair with the Swap button and compare direction.
Final thoughts
A reliable interval calculator is a powerful companion for theory homework, songwriting, and daily ear training. Use it to check your work, then challenge yourself to identify intervals mentally before clicking the button. Over time, you’ll internalize both the sound and spelling of intervals, which is where real musical freedom begins.