Chord Note Frequencies Calculator
Every note in equal temperament sits a whole number of semitones from a reference pitch, and each semitone multiplies frequency by the twelfth root of 2. This calculator takes a root frequency and the semitone offsets of three upper chord tones, then returns the exact frequency of each note. The defaults give a major triad (0, 4 and 7 semitones). Change the offsets for minor, seventh, or extended chords, and change the root frequency to match your tuning reference.
Chord frequency formula
tone frequency = root * 2^(semitone offset / 12)
root = root * 2^(0 / 12)
major third = root * 2^(4 / 12)
perfect fifth = root * 2^(7 / 12)
octave = root * 2^(12 / 12) = root * 2
Equal temperament splits the octave into 12 equal semitones, each a frequency ratio of 2^(1/12). A tone n semitones above the root is therefore the root multiplied by that ratio raised to the n.
Common chord semitone offsets
- Major triad: 0, 4, 7.
- Minor triad: 0, 3, 7.
- Diminished triad: 0, 3, 6.
- Dominant seventh: 0, 4, 7, 10.
- Major seventh: 0, 4, 7, 11.
Chord frequencies: frequently asked questions
How are chord note frequencies calculated?
In equal temperament each semitone multiplies frequency by the twelfth root of 2. A note that is n semitones above the root has frequency root times 2^(n/12). A major triad uses semitone offsets of 0, 4 and 7 above the root.
What semitone offsets make a major chord?
A major triad is the root (0 semitones), the major third (4 semitones) and the perfect fifth (7 semitones). A minor triad uses 0, 3 and 7. Enter the offsets for the chord you want and the calculator returns each tone's frequency.
Why use equal temperament rather than just intonation?
Equal temperament divides the octave into 12 equal semitones, so chords sound consistent in every key, which is how pianos and most digital instruments are tuned. Just intonation uses small whole-number ratios that sound purer in one key but drift in others.
What is the frequency of A4 and why does it matter?
A4 is the standard tuning reference, commonly 440 Hz (ISO 16). All other equal-tempered frequencies are derived from this reference, so changing the root frequency to your tuning pitch rescales every chord tone proportionally.
Can I calculate a four-note or extended chord?
Yes. Enter the semitone offset of the fourth tone, for example 10 for a minor seventh or 11 for a major seventh. The calculator returns its frequency the same way as the triad tones.
Official sources
- National Institute of Standards and Technology: SI units and frequency.
- International Organization for Standardization: ISO 16 standard concert pitch (A4 = 440 Hz).
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.