Piano Intervals Calculator

This piano intervals calculator helps musicians and music theory students determine the distance between two piano keys in semitones and identify the musical interval name. Whether you're composing, practicing scales, or analyzing music, understanding intervals is fundamental to musical understanding.

What is a Piano Interval?

In music theory, an interval is the distance between two pitches. On a piano, intervals are measured in semitones - the smallest distance between two adjacent keys. The number of semitones between two notes determines the interval name and quality (major, minor, perfect, etc.).

Types of Intervals

Musical intervals are categorized by their size and quality:

Perfect Intervals: Unison (0 semitones), Fourth (5 semitones), Fifth (7 semitones), Octave (12 semitones)
Major Intervals: Major Second (2 semitones), Major Third (4 semitones), Major Sixth (9 semitones), Major Seventh (11 semitones)
Minor Intervals: Minor Second (1 semitone), Minor Third (3 semitones), Minor Sixth (8 semitones), Minor Seventh (10 semitones)
Diminished Intervals: One semitone smaller than the minor version
Augmented Intervals: One semitone larger than the major version

Interval Quality

The quality of an interval describes its harmonic character:

Major: Bright, happy sound
Minor: Sad, tense sound
Perfect: Pure, consonant sound
Diminished: Dark, unstable sound
Augmented: Bright but unstable sound

How to Use This Calculator

Using the piano intervals calculator is simple:

Select the starting note from the dropdown menu
Select the ending note from the dropdown menu
Click "Calculate Interval" to see the results
Review the interval name, semitones, and quality
Use the visualization to understand the interval's position on the piano

Note: The calculator assumes a standard 12-tone equal temperament tuning system used in most modern pianos.

Formula Used

The interval between two piano keys is calculated using the following formula:

Interval = (Ending Note - Starting Note) mod 12

Where:

Starting Note = MIDI note number of the first key
Ending Note = MIDI note number of the second key
mod 12 = Modulo operation to find the equivalent interval within one octave

The result is then mapped to the standard musical interval names based on the number of semitones between the notes.

Worked Examples

Example 1: C to E

Starting Note: C (MIDI 60)

Ending Note: E (MIDI 64)

Calculation: (64 - 60) mod 12 = 4 semitones

Result: Major Third (4 semitones)

Example 2: F to B♭

Starting Note: F (MIDI 65)

Ending Note: B♭ (MIDI 66)

Calculation: (66 - 65) mod 12 = 1 semitone

Result: Minor Second (1 semitone)

Example 3: G to D

Starting Note: G (MIDI 67)

Ending Note: D (MIDI 62)

Calculation: (62 - 67) mod 12 = 11 semitones (since -5 mod 12 = 7)

Result: Major Sixth (9 semitones) - Wait, this shows a calculation error. The correct calculation for descending intervals should be (Starting Note - Ending Note) mod 12 = (67 - 62) mod 12 = 5 semitones, which is a Perfect Fourth.

FAQ

What is the difference between a major and minor interval?

A major interval has a brighter, happier sound, while a minor interval has a darker, more tense sound. The difference is typically one semitone.

How do I identify an interval on the piano?

Count the number of keys between the two notes, including both notes. The number of keys minus one equals the number of semitones.

What is the largest interval on the piano?

The largest interval is the octave, which spans 12 semitones or 13 keys (including both notes).

Can this calculator work with microtonal intervals?

No, this calculator assumes standard 12-tone equal temperament tuning. Microtonal intervals would require a different calculation method.