Calculadora de Intervalo Musical
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
semitom = |n2 − n1| mod 12
About this calculator
The Musical Interval Calculator determines the distance in semitones between two notes and provides the corresponding interval name. It is useful for musicians, composers, and music theory students who need to quickly identify intervals like major third, perfect fifth, minor seventh, etc. The tool considers notes from C to B, including sharps and flats, and calculates the chromatic difference between them.
How it works: you select the first note and the second note from dropdown menus. The calculator then converts each note to an integer (C=0, C#=1, D=2, etc.), computes the absolute difference between these numbers, and applies modulo 12 to get the number of semitones. Based on that value, it returns the interval name (e.g., 0 semitones = unison, 1 = minor second, 2 = major second, and so on).
When to use? In situations like transposing songs, harmonic analysis, composition, or when learning intervals on an instrument. For example, a guitarist can use it to find that the distance between E and G is 3 semitones (minor third). The calculator is practical to avoid manual counting and naming errors.
Cautions: The calculator assumes equal temperament (12 equal semitones). It does not consider enharmonic differences (e.g., C# vs. Db), both are treated as the same note. Also, compound intervals (larger than an octave) are not supported; the result always stays within one octave (0-11 semitones).
Frequently asked questions
What does 'semitone' mean?
A semitone is the smallest distance between two notes in Western music, equivalent to one fret on a guitar or one adjacent piano key (including black keys).
How does the calculator handle enharmonic notes like C# and Db?
The calculator treats C# and Db as the same note (value 1), so the interval will be the same regardless of the naming.
Why is the maximum interval 11 semitones (major seventh)?
Because the calculation uses modulo 12, limiting the result to one octave. Intervals larger than an octave (e.g., ninth) are reduced to their equivalent within the octave.
Can I use this calculator to transpose an entire song?
Yes, but you need to calculate the interval between the original key and the new key, then apply the same distance to each note of the melody.
Does the calculator work for notes with accidentals like B# or Fb?
Yes, as long as the note is in the available list (includes sharps and flats). B# is treated as C, and Fb as E.