Music Interval Calculator
Identify the interval between written notes or between two equal-tempered pitches, with optional semitone and tone distances.
Interval inputs
Live result
How to use the Music Interval Calculator
What this calculator does
This calculator identifies the musical distance from Note 1 to Note 2. In Between notes mode it treats spelling as meaningful, so enharmonic notes can produce different theory names: C to C♯ is an augmented prime, while C to D♭ is a minor second, even though C♯ and D♭ can sound at the same pitch in twelve-tone equal temperament. In Between pitches mode it ignores that spelling distinction and measures the sounding semitone distance across nine numbered octaves. The result is an interval identity, not a judgment about consonance, chord function, key, or voice-leading.
Intervals are foundational measurements for melody and harmony. The University of Puget Sound's introduction to musical intervals explains the distinction between melodic and harmonic intervals and why interval measurement is central to scales and chords.
When to use it
- Check written interval homework where accidentals and note letters determine whether an interval is major, minor, perfect, augmented, or diminished.
- Measure the distance between two keyboard, fretboard, MIDI-style, or synthesized pitches when the enharmonic spelling is irrelevant.
- Confirm transposition distances, ear-training answers, or a compound interval that extends beyond one octave.
How to calculate
The calculator opens with a complete demonstration: Between notes, C to G, with Show semitones/tones enabled. That example immediately returns a perfect fifth, 7 semitones, or 3.5 tones, and its Excel workbook is ready to download.
- Choose Interval type. Keep Between notes when written spelling matters, or switch to Between pitches to choose numbered pitches from C0 through B8.
- Select Note 1, then Note 2. The second note must not lie below the first in the chosen interpretation. In written-note mode, the calculator follows an ascending letter span within one notated octave; in pitch mode, it compares the numbered pitch positions directly.
- Leave Show semitones/tones on if you want the numeric distance as well as the interval name. Turn it off for a cleaner theory-only result.
- Read Interval first. For pitch distances from 13 through 28 semitones, Simple interval also shows the octave-reduced identity. Semitones and Tones are visible only when the display option is enabled.
- Select Download Excel to export the current inputs and results as a validated XLSX workbook. Reset clears the demonstration notes and results; after Reset, Excel export is disabled until both required notes form a valid interval again.
Input guide
Interval type is a required two-option selector. Between notes expects written note names using a letter plus an optional single flat or sharp, such as F♯ or B♭. Between pitches expects one of the listed chromatic pitches with an octave number, such as A4 or C♯/D♭5. Changing the mode changes what the note selectors mean, so recheck both selections after switching.
Note 1 is required and represents the lower or starting note. A realistic written-note example is C; a realistic pitch example is A4. Note 2 is also required and represents the higher or ending note; G or E5 are typical examples. In written-note mode, accidentals alter the semitone size without changing the letter count, which is exactly why C – F♯ is an augmented fourth while C – G♭ is a diminished fifth. A common mistake is treating enharmonic spelling as interchangeable during theory analysis.
Show semitones/tones is an optional checkbox. When selected, the calculator displays the chromatic distance as whole semitones and half-as-large tone units. It does not change the interval itself. One tone equals two semitones in this calculator, so a 7-semitone perfect fifth is 3.5 tones.
Output guide
Interval is the primary result. In written-note mode it combines interval number and quality, including diminished and augmented forms. In pitch mode it uses the conventional semitone-based simple name up to an octave, formal compound names through 28 semitones, then an explicit “octaves plus interval” description for larger distances. Simple interval appears only for pitch intervals from 13 to 28 semitones and gives the octave-reduced identity. Semitones is the exact chromatic step count for the selected pair; Tones is exactly half that number. A zero-semitone result means unison or, in written notation, a theoretically altered interval whose pitches coincide.
Worked example
With the startup values C to G, count the note letters inclusively: C(1), D(2), E(3), F(4), G(5), so the generic size is a fifth. Then count chromatic steps: C→C♯(1), D(2), D♯(3), E(4), F(5), F♯(6), G(7). A fifth that spans 7 semitones is perfect, so the displayed result is Perfect fifth, with 7 semitones and 3.5 tones. For a structured method of identifying interval quality, see the University of Puget Sound's interval-identification guide.
How interval naming and pitch distance relate
Written interval names contain two pieces of information. The number comes from the span of note letters, counted inclusively, while the quality depends on chromatic distance. Unisons, fourths, fifths, and octaves belong to the perfect family; seconds, thirds, sixths, and sevenths belong to the major/minor family. Raising or lowering either note by a semitone changes the quality in a predictable direction. This is why the same piano key can participate in differently named intervals depending on whether it is spelled with a sharp or a flat.
In twelve-tone equal temperament, adjacent chromatic pitches have the same frequency ratio, and twelve semitones make one octave. The University of New South Wales' note-frequency reference explains that an octave is a 2:1 frequency ratio and that each equal-tempered semitone therefore has a ratio of 21/12. That physical relationship supports the pitch-mode semitone count, but the calculator intentionally does not display frequencies because its core task is interval identification rather than tuning analysis.
Compound intervals extend beyond an octave. A ninth is an octave plus a second, a tenth is an octave plus a third, and so on. For moderately sized compound intervals, seeing both the compound and simple names helps connect the result to familiar octave-reduced theory. For very large distances, an “octaves plus interval” description is usually easier to read than increasingly uncommon ordinal names.