Chord Progression Calculator - Preset Progressions in Any Key

A chord progression calculator turns a Roman-numeral pattern like I - V - vi - IV into the chord names played in any key. Choose a tonic, a major or natural-minor scale, and a preset; the result shows the Roman numerals and the resolved chord names side by side so you can transpose a familiar progression without rewriting it by hand.

• • Learn a song in your own key: Render a song's progression in a key that matches your vocal range and read the chord names directly off the screen.
• • Transpose a Pachelbel, 12-bar blues, or ii-V-I: Use a named preset to see the same Roman numerals resolved into chord names for any of the 12 chromatic keys.
• • Compare major and minor versions: Switch the scale toggle to see how the chord qualities change, which helps when verse and chorus are in parallel modes.
• • Teach or study diatonic harmony: Display the I-ii-iii-IV-V-vi-vii° quality pattern that drives every preset as a quick reference during lessons or ear training.

Every preset is built on the diatonic chord-quality pattern of a single scale, so the difference between I-IV-V in C major and I-IV-V in A minor is a transposition plus a re-spelling of the chord roots; the tool handles that for all 12 keys.

For a deeper dive on a single chord, see the chord calculator reference, and to shift a finished progression into a different key you can also pair this with the chord transposer.

The calculator combines a key, a major or natural-minor scale, and a preset Roman-numeral pattern, then resolves each Roman numeral into a chord by walking the diatonic note at that degree and applying the scale's quality rule.

• key: Tonic note; the Key dropdown lists all 12 pitch classes with both spellings, so flat keys (Db, Eb, Gb, Ab, Bb) are picked directly and render with flat-spelled chord names.
• scaleMode: Major or natural minor; sets the quality pattern (I-ii-iii-IV-V-vi-vii° or i-ii°-III-iv-v-VI-VII).
• progressionId: Preset Roman-numeral pattern such as Pachelbel's Canon (I-V-vi-iii-IV-I-IV-V) or the 12-bar blues (I-I-I-I-IV-IV-I-I-V-IV-I-I).
• accidental (b or #): Optional flat or sharp on a borrowed degree such as bVII; the calculator lowers or raises the diatonic note by one semitone before spelling the chord.

The major-scale pattern is I (major), ii (minor), iii (minor), IV (major), V (major), vi (minor), vii° (diminished), and the natural-minor pattern is i, ii°, III, iv, v, VI, VII, so the only thing that changes between keys is the spelling of the root notes plus the matching quality label.

According to Open Music Theory, the diatonic triads of a major scale are I (major), ii (minor), iii (minor), IV (major), V (major), vi (minor), and vii° (diminished).

To shift a finished progression into a different key you can also pair this with the chord transposer.

These four concepts are the building blocks every preset in the calculator is built on, and they are enough to understand why a progression sounds the way it does.

For work on a single chord at a time, the chord finder lists the notes inside each triad, and for a deeper dive on inversions the chord inversion calculator shows the same chord with the bass note in a different position.

Build any of 12 common progressions in your chosen key in three quick steps. The result pairs the Roman-numeral pattern with the actual chord names side by side, so you can read either notation off the screen.

1. 1 Choose a key: Select the tonic note from the Key dropdown. The list covers all 12 pitch classes with both spellings (Db, Eb, Gb, Ab, and Bb are listed directly), and any flat key renders with flat-spelled chord names like Db-F-Ab rather than the sharp enharmonic.
2. 2 Choose major or natural minor: Major uses the bright I-ii-iii-IV-V-vi-vii° quality pattern; natural minor uses the darker i-ii°-III-iv-v-VI-VII pattern.
3. 3 Pick a progression preset: Choose from 12 common patterns: Pachelbel, 12-bar blues, ii-V-I, I-V-vi-IV, 50s, Andalusian, circle progression in minor, and Montgomery-Ward bridge.
4. 4 Read the Roman numerals and chord names: The Roman numeral row keeps the pattern; the chord-name row resolves each numeral into the actual chord in the chosen key.
5. 5 Switch keys to transpose: Change the Key dropdown to move the entire progression. The Roman-numeral pattern stays the same; only the chord names update.
6. 6 Copy or reset: Use Reset to return to the default key, scale, and preset, or copy the chord-name row into your own chart.

A song is in C major but you need to play it in Bb for a singer's range. Pick Key = Bb, Scale = major, and the song's I - IV - V. The Roman numerals stay I - IV - V while the chord names switch from C - F - G to Bb - Eb - F, a whole step lower.

Use the chord inversion calculator when the progression includes slash chords or bass-note inversions that the root-position view here does not show.

A chord progression calculator saves time on the same five tasks musicians, students, and teachers repeat for almost every new song.

• • Transpose a progression in seconds: Switch the Key dropdown and the chord names update; no more manual shifting of every chord by one fret or semitone.
• • See the diatonic quality pattern next to the result: Each preset shows the Roman-numeral pattern and the resolved chord names side by side, which makes the I/IV/V major rule and the ii/iii/vi minor rule obvious.
• • Compare major and minor versions: Flipping the Scale toggle between major and natural minor gives you the parallel-mode pair for any preset, useful for songwriting and explaining borrowed chords in lessons.
• • Learn 12 common patterns in one place: Pachelbel, 12-bar blues, ii-V-I, I-V-vi-IV, 50s, Andalusian, the circle, the axis, and the Montgomery-Ward bridge are all here in one tool.
• • Stay in the right spelling for flat keys: Db major shows as Db - Gb - Bbm - Fm rather than C# - G# - A#m - F#m, matching printed lead sheets and chord charts.

For work on a single chord, the chord calculator and chord finder complement the progression view by showing the notes and intervals of one chord at a time, and the chord transposer is the right tool when you only need to shift a finished progression without rebuilding the Roman-numeral pattern.

A few things determine which chord a Roman numeral becomes, and being aware of them prevents the wrong chord from showing up in a chart.

• • The calculator only renders root-position triads; seventh, ninth, or suspended extensions are not added, so a Cmaj7 input will still come out as C major triad with the seventh to add by hand.
• • In a natural-minor key, an uppercase V is shown as a major dominant (E major in A minor) which matches classical practice; harmonic- and melodic-minor songs should confirm the V quality by ear.

If the song uses inversions or seventh-chord extensions, run the same progression through the chord inversion calculator after picking the key here.

According to Wikipedia (Chord progression), a chord progression is a succession of chords played one after another, and the most common patterns in popular and classical music include I-IV-V, I-V-vi-IV, the 12-bar blues, the ii-V-I jazz cadence, and the Pachelbel Canon.

According to Wikipedia (Pachelbel's Canon), the piece repeats an eight-chord ground bass in the order I-V-vi-iii-IV-I-IV-V over a 28-bar form, the same diatonic shape the calculator renders when you pick the Pachelbel preset.