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Interval Calculator
Find the musical interval between any two notes. See interval name, semitones, cents, frequency ratio, consonance rating, and listen with melodic or harmonic playback.
Select Two Notes
261.63 Hz
392.00 Hz
Or click two notes on the keyboard
Click the first note
Playback
Interval Result
Perfect 5th
P5
Semitones
7
Cents
700
Frequency Ratio
3:2
Quality
Perfect
Consonance
Perfect consonance
Inversion:
P5 inverts to P4
Note 1:
C4 (261.63 Hz)
Note 2:
G4 (392.00 Hz)
Direction:
Ascending
Complete Interval Reference Table
| Interval Name | Short | Semitones | Cents | Ratio | Quality | Consonance |
|---|
How to Use the Interval Calculator
Step 1: Select Two Notes
Use the dropdown selectors to choose a note name and octave for each note, or click two notes on the interactive piano keyboard. The first note you select becomes Note 1, the second becomes Note 2.
Step 2: Read the Result
The result panel instantly shows the interval name, semitone distance, cent value, frequency ratio, quality (perfect, major, minor, augmented, diminished), and consonance/dissonance classification.
Step 3: Listen and Explore
Use the playback buttons to hear the interval melodically (notes played one after the other, ascending or descending) or harmonically (both notes sounding together). Check the inversion and compound interval info below the result.
Understanding Musical Intervals
A musical interval is the distance in pitch between two notes. Intervals are measured in semitones (half steps) and can be described by their quality (perfect, major, minor, augmented, diminished) and their numerical size (unison, 2nd, 3rd, etc.). The frequency ratio between two notes determines the interval's acoustic character and its perceived consonance or dissonance.
Semitones and Cents
cents = semitones x 100
One semitone equals 100 cents in 12-tone equal temperament. An octave spans 12 semitones (1200 cents). Cents allow precise measurement of intervals smaller than a semitone.
Interval Inversion
inversion = 12 - semitones
Every interval within an octave has a complementary inversion that sums to 12 semitones. A perfect 5th (7 semitones) inverts to a perfect 4th (5 semitones). Major inverts to minor and vice versa.
Consonance and Dissonance
- Perfect consonance — Unison, perfect 4th, perfect 5th, and octave. These intervals have the simplest frequency ratios (1:1, 4:3, 3:2, 2:1) and sound the most stable.
- Imperfect consonance — Major and minor 3rds and 6ths. These intervals are pleasing but have a warmer, more complex quality than perfect consonances.
- Mild dissonance — Major 2nd and minor 7th. These intervals create gentle tension that is common in many musical styles.
- Sharp dissonance — Minor 2nd, major 7th, and tritone. These intervals produce strong tension and are often used for dramatic effect or to create a sense of instability.
Frequently Asked Questions
What is a musical interval?
A musical interval is the difference in pitch between two notes. It is measured in semitones (half steps) and described by a quality (perfect, major, minor, augmented, diminished) and a numeric size (unison, 2nd, 3rd, 4th, etc.). For example, the interval from C to G is a perfect 5th, spanning 7 semitones.
What is the difference between a melodic and a harmonic interval?
A melodic interval occurs when two notes are played one after another in sequence. A harmonic interval occurs when two notes are played simultaneously. The same two notes produce the same interval name either way, but the musical effect is different: melodic intervals create a sense of motion, while harmonic intervals create a sense of color or texture.
What is interval inversion?
Interval inversion is the process of flipping an interval by moving the lower note up an octave (or the upper note down an octave). The inversion of any simple interval sums to 12 semitones with the original. For example, a perfect 5th (7 semitones) inverts to a perfect 4th (5 semitones), and a major 3rd (4 semitones) inverts to a minor 6th (8 semitones).
What is a compound interval?
A compound interval spans more than one octave. For example, a minor 9th (13 semitones) is an octave plus a minor 2nd. Compound intervals have the same quality and consonance characteristics as their simple counterparts but with a wider, more spacious sound. This calculator identifies compound intervals and shows their octave-plus-simple-interval equivalents.
Why does the tritone have two names (A4/d5)?
The tritone (6 semitones) sits exactly in the middle of the octave and can be spelled as either an augmented 4th (A4) or a diminished 5th (d5), depending on the musical context. Both names refer to the same pitch distance. Historically called "diabolus in musica" (the devil in music), the tritone is the most dissonant interval within the octave and has a uniquely restless, unstable quality.
What do the frequency ratios mean?
Frequency ratios describe the mathematical relationship between two pitches. A perfect 5th has a ratio of 3:2, meaning the higher note vibrates 1.5 times as fast as the lower note. Simpler ratios (like 2:1 for an octave or 3:2 for a perfect 5th) produce more consonant-sounding intervals, while complex ratios (like 16:15 for a minor 2nd) produce dissonance. These ratios come from just intonation; equal temperament approximates them.