Chord Transposer

Shift a chord progression into a new key using chromatic (semitone) transposition. Enter your chords and the original and new key to get the transposed chords, the shift interval, and a capo-fret equivalent.

Quick Facts

Method
Chromatic semitone shift (mod 12)
Each chord root moves the same number of semitones through the 12-note chromatic scale; the chord quality and any slash-bass note are preserved.
Capo shortcut
Capo fret = semitones shifted up
Playing the original chord shapes with a capo on fret N raises the pitch by N semitones - the same result as transposing up N steps.

Your Results

Calculated
Transposed chords
-
New progression in the target key
Semitone shift
-
Chromatic steps from original to new key
Interval
-
Music-theory name for the shift
Capo equivalent
-
Play original shapes with a capo

Ready

Enter a chord progression, pick the original and new key, then press Calculate.

About the Chord Transposer

This tool shifts a chord progression from one key into another using chromatic transposition — the standard method musicians, arrangers, and songbook editors use to change key. Every note in Western music sits at one of 12 positions in the chromatic scale (C, C#, D, D#, E, F, F#, G, G#, A, A#, B), and moving from an original key to a new key is simply a fixed number of semitone steps applied to every chord root in the progression.

The formula

Number the 12 chromatic notes 0 through 11 starting at C. The shift between two keys is shift = (newKeyIndex − originalKeyIndex) mod 12, which always produces a value from 0 to 11 semitones "up." Every chord's root is then re-indexed as newRootIndex = (originalRootIndex + shift) mod 12. The chord's quality — major, minor (m), seventh (7), suspended (sus4), diminished (dim), major seventh (maj7), and so on — is left untouched, because quality describes the relationship between notes within the chord, not the chord's absolute pitch. A slash chord such as G/B has its bass note transposed by the same shift, independently of the root.

How to get the best results

  • Type chord names separated by spaces, using a root of A–G with an optional # or b (sharp or flat), e.g. G D Em C or F#m7 Bm D A
  • Set the original key to the key the progression is currently in, and the new key to the key you want to move it to
  • If your instrument reads flats (like many horn or band charts), switch Output notation to Flats so the spelling matches your sheet music

Practical context

Transposition is used to fit a song to a singer's vocal range, to make a chart playable on a capo-friendly set of guitar shapes, or to match a fixed-pitch instrument such as a Bb trumpet or Eb saxophone. The chromatic shift shown here is exact for standard equal-temperament tuning; it does not decide which key sounds "best" for a given voice or instrument — that judgment still belongs to the musician.

Frequently Asked Questions

How does chord transposition work?
Each chord root sits at one of 12 positions in the chromatic scale (C, C#, D, D#, E, F, F#, G, G#, A, A#, B). Transposing shifts every root by the same number of semitones and wraps around after B back to C (that is, modulo 12). The chord quality - m, 7, sus4, dim, maj7, and so on - and any slash-bass note travel with the new root unchanged.
What does the capo suggestion mean?
Placing a capo on fret N of a guitar raises every open chord shape by N semitones - the same pitch change as transposing up N steps. So if the calculator finds a 7-semitone shift, playing the original chord shapes with a capo on fret 7 sounds identical to the transposed chords played open, with no new shapes to learn.
Why choose between sharps and flats?
Sharps and flats are two names for the same pitch (D# and Eb sound identical). Which spelling is conventional depends on the target key - keys like D, A, and E traditionally use sharps, while F, Bb, and Eb traditionally use flats. Use the Output notation option to match how your sheet music or band is written.
Can I transpose slash chords and chords outside the key?
Yes. A slash chord such as G/B has its root (G) and its bass note (B) transposed independently, so the interval between them is preserved. Any chord you type with a root of A through G and an optional # or b is recognized and shifted, whether or not it belongs to the diatonic scale of the original key.

Related calculators