Music Interval Calculator
Calculate the interval between two notes with strict spelling, sound-only pitch distance, piano mapping, inversion, consonance, tones, and equal-temperament ratio.
Find the exact interval name from note spelling
A music interval calculator identifies the distance between two notes. It returns both the chromatic distance in semitones and the diatonic interval name, such as minor third, perfect fifth, or augmented fourth.
Note spelling matters. C to F# and C to Gb both span 6 semitones, but the first is an augmented fourth and the second is a diminished fifth.
Use this tool for ear training, harmony homework, transposition checks, chord spelling, and music theory practice.
Switch between written-note analysis and sound-only pitch distance when you want to compare notation with what the keyboard actually plays.
Interval name
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Spelled name
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Sound-only
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Semitones
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Whole tones
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Number
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Inversion
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Consonance
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ET ratio
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Piano pitch map
The highlighted keys show the starting and target pitch classes.
Chromatic distance
Each chip represents one semitone in the calculated direction.
Calculation steps
Use these steps to show how the interval was named.
1. Count note letters
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2. Count semitones
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3. Compare with the expected interval
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Pitch Distance Vs Written Interval
A keyboard can make two spellings sound identical, but notation still treats them differently. Use sound-only mode when you care about the pitch distance. Use spelled-note theory when you care about the written interval in a score.
| Entered notes | Sound-only answer | Spelled-note answer | Why it changes |
|---|---|---|---|
| C to C# | Minor second sound | Augmented unison | The letter stays C, so the interval number is a unison. |
| C to Db | Minor second sound | Minor second | C to D is a second by letter count. |
| C to F# | Tritone sound | Augmented fourth | C to F is a fourth, then the sharp widens it. |
| C to Gb | Tritone sound | Diminished fifth | C to G is a fifth, then the flat narrows it. |
The strongest interval answer depends on the job. For ear training, the sound-only answer is often enough. For harmony, counterpoint, transposition, exams, notation, and chord spelling, the written-note answer is usually the one that matters.
Common Simple Intervals
This chart shows the usual semitone distance for common simple intervals within one octave.
| Semitones | Common interval | Example |
|---|---|---|
| 0 | Perfect unison | C to C |
| 1 | Minor second | C to Db |
| 2 | Major second | C to D |
| 3 | Minor third | C to Eb |
| 4 | Major third | C to E |
| 5 | Perfect fourth | C to F |
| 6 | Augmented fourth or diminished fifth | C to F# or C to Gb |
| 7 | Perfect fifth | C to G |
| 8 | Minor sixth | C to Ab |
| 9 | Major sixth | C to A |
| 10 | Minor seventh | C to Bb |
| 11 | Major seventh | C to B |
| 12 | Perfect octave | C to C, one octave higher |
Reference on interval number and quality: University of Puget Sound: Introduction to Intervals.
Interesting Fact
In 12-tone equal temperament, an octave is divided into 12 equal semitones. Each semitone has a frequency ratio of 2^(1/12), about 1.05946, according to Physics LibreTexts. That means moving up one semitone raises frequency by about 5.946%, while 12 semitones doubles the frequency and creates an octave.
How Interval Names Work
Every interval name has two parts: a number and a quality.
The number comes from letters
Count both note letters, including the starting and ending notes. C to E uses C, D, and E, so it is some kind of third. C to F uses C, D, E, and F, so it is some kind of fourth.
The quality comes from semitones
After the number is known, compare the semitone count with the expected major or perfect form. Lowering or raising notes creates minor, augmented, or diminished intervals.
Reference on ear training as a musicianship skill: Berklee College of Music: Ear Training Core.
Worked Examples
These examples show why spelling and direction matter.
C to E
C to E counts as a third and spans 4 semitones, so the interval is a major third.
C to Eb
C to Eb is still a third, but it spans 3 semitones, so the interval is a minor third.
C to Gb
C to Gb spans 6 semitones, but the letters C through G make it a fifth, so the interval is a diminished fifth.
Interval Quality Rules
Use these rules when you want to check the calculator's answer by hand.
| Interval family | Normal quality | If smaller | If larger |
|---|---|---|---|
| Unison, fourth, fifth, octave | Perfect | Diminished | Augmented |
| Second, third, sixth, seventh | Major | Minor, then diminished | Augmented |
| Enharmonic intervals | Depends on spelling | C to Gb is a diminished fifth | C to F# is an augmented fourth |
Practical shortcut: first count the letters to get the interval number, then count semitones to get the quality. This avoids the most common mistake, which is naming an interval only from its piano-key distance.
Ear Training With Intervals
Interval recognition is easier when you connect the theory name to a repeatable listening habit.
Listen for size first
Decide whether the interval sounds like a step, skip, leap, octave, or wide compound interval before worrying about the exact name.
Then hear quality
Major intervals often feel brighter, minor intervals often feel darker, perfect intervals sound stable, and tritones usually sound tense or unresolved.
Practice both directions
Ascending and descending versions of the same interval can feel different. Practice both so the label is tied to the actual sound, not just a memorized chart.
How Intervals Build Chords And Harmony
Intervals are not just isolated distances. They explain chord quality, melodic motion, and harmonic tension.
| Interval | Musical role | Why it matters |
|---|---|---|
| Thirds | Define major or minor chord quality | A major third above the root suggests a major chord; a minor third suggests a minor chord. |
| Perfect fifth | Stabilizes triads | The fifth supports the root and helps make many chords sound grounded. |
| Tritone | Creates strong tension | The augmented fourth or diminished fifth often wants to resolve by step in tonal harmony. |
| Sevenths | Add color and pull | Seventh intervals help distinguish dominant, major seventh, minor seventh, and diminished seventh chords. |
Reference on triads and interval structure: Open Music Theory: Triads.
Interval Practice Lab
Load a scenario, predict the answer, then compare the spelled-note name with the sound-only name in the calculator.
Music theory answers
Frequently Asked Questions
Quick answers for interval spelling, semitone counting, inversions, and how intervals work in melody and harmony.
01 What does a music interval measure?
A music interval measures the distance from one note or pitch to another. An interval calculator can describe that distance by semitone count, such as 7 semitones, and by its music theory name, such as perfect fifth.
02 Why do enharmonic notes create different interval names?
An enharmonic note can sound the same as another note on a piano keyboard or guitar fretboard, but it uses a different letter name in staff notation. Since the interval number comes from the root note and target note letters, C to F# is an augmented fourth while C to Gb is a diminished fifth.
03 How do interval quality and interval number work together?
The interval number is found by counting letter names, while the interval quality is found by checking the semitone distance. For example, C to E is a third by letter count, and its 4-semitone distance makes it a major third.
04 What is an interval inversion?
An inversion flips an interval so the lower note becomes the upper note, or the upper note becomes the lower note. Major intervals invert to minor intervals, augmented intervals invert to diminished intervals, and perfect intervals stay perfect, which is useful when analyzing chord voicings and harmony.
05 What is the difference between a simple and compound interval?
A simple interval fits within one octave, such as a major third or perfect fifth. A compound interval is larger than an octave, such as a major tenth, which sounds like a major third with an added octave and often appears in wider melodies or open chord voicings.
06 What is the difference between melodic and harmonic intervals?
A melodic interval happens when two notes are played one after the other, as in a scale or melody. A harmonic interval happens when the notes sound at the same time, which is common in chords, harmony analysis, and ear training exercises.
07 Should I use sound-only mode or spelled-note mode?
Use sound-only mode when you want the pitch distance you would hear on a keyboard or fretboard. Use spelled-note mode when the written notes matter, such as music theory homework, chord spelling, transposition, notation, counterpoint, or score analysis.
Disclaimer
This music interval calculator is provided for general educational and informational purposes only. It is intended to help with music theory practice, ear training, notation review, and informal learning. It is not a substitute for instruction from a qualified teacher, review by a school or examination board, professional music preparation, publishing review, or any other expert assessment.
Results are based on the note spelling, accidentals, direction, and octave information entered by the user, together with common Western music theory conventions. Music theory usage can vary by curriculum, temperament, tuning system, historical style, notation context, instrument, editorial policy, and regional convention. Enharmonic equivalents may sound the same in equal temperament while carrying different theoretical names. Users are responsible for checking whether a result fits their specific score, assignment, exam, composition, arrangement, performance, or publication context.
Although reasonable care is taken to make the calculator useful, no representation or warranty is made that the tool, formulas, examples, explanations, interface, or output will be accurate, complete, current, uninterrupted, secure, error-free, or suitable for any particular purpose. The calculator and all related content are provided "as is" and "as available" without warranties of any kind, express or implied, including warranties of merchantability, fitness for a particular purpose, title, non-infringement, or course-related acceptance.
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Any examples, charts, explanations, or FAQ content are simplified learning aids and should not be treated as exhaustive statements of music theory. If accuracy matters, verify the interval with a trusted teacher, official course material, examination syllabus, style guide, publisher, musicologist, or other qualified source before relying on the result.
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Last updated: June 3, 2026