# Chord Progression Calculator

URL: https://speedycalculator.com/calculators/other/chord-progression/
Last updated: 2026-10-30

> The chord progression calculator turns Roman-numeral progressions – classic presets such as I–V–vi–IV, ii–V–I, the 12-bar blues or the Andalusian cadence, or your own numerals – into chord names and notes in any major or minor key, and lists the diatonic chords of the key.

## Inputs

- Progression
- Key (tonic)
- Key quality (custom progression)
- Custom progression (Roman numerals) — Separate with spaces. Examples: I V vi IV · ii7 V7 Imaj7 · i bVI bVII i · I7 IV7 · vii°7. Use b or ♭ for lowered roots.

## Results

- Chords
- Roman numerals
- Key and key signature
- Chords and their notes
- Diatonic triads of the key
- Diatonic seventh chords of the key
- Scale of the key

## Formula

```
Chord root = scale degree of the key (major or natural minor), altered by ♭/♯
Upper-case numeral = major · lower-case = minor · ° = diminished · + = augmented
Major key: I ii iii IV V vi vii° · natural minor: i ii° III iv v VI VII
```

## Explanation

Chord progressions are usually taught with Roman numerals because the numerals describe the pattern, not the key: I–V–vi–IV is the same progression whether it is C–G–Am–F in C major or E–B–C♯m–A in E major. The numeral gives the scale degree of the chord root, its case gives the quality (upper case major, lower case minor) and extra symbols add details such as ° for diminished, + for augmented or 7 for a seventh chord.

Pick a preset or type your own numerals, choose a key and the calculator spells every chord in that key, including chromatic chords such as ♭VII or a major V in a minor key. Use it to transpose a song to a singer’s range, to try a progression in a new key on your instrument, or to learn why so many songs share the same handful of chord patterns.

Below the result you also get the seven diatonic triads and seventh chords of the key – the “family” of chords that sound natural together – and the key’s scale on a keyboard.

### How to use the Chord Progression Calculator

- **Progression**
- **Key (tonic)**
- **Key quality (custom progression)**
- **Custom progression (Roman numerals)** — Separate with spaces. Examples: I V vi IV · ii7 V7 Imaj7 · i bVI bVII i · I7 IV7 · vii°7. Use b or ♭ for lowered roots.

Everything is calculated in your browser, so results appear instantly and nothing you type is sent to a server.

### How it works

Each numeral is converted to a scale degree (I = 1st … VII = 7th) of the chosen key’s major or natural minor scale; a ♭ or ♯ before it lowers or raises that root. The case and suffix select the chord type, and the chord is spelled from its root. Diatonic chords are built by stacking every other note of the scale.

### Worked example

The Andalusian cadence i – VII – VI – V in **A minor**: the natural minor scale is A, B, C, D, E, F, G. Degree 1 minor = Am, degree 7 major = G, degree 6 major = F, and the upper-case V on degree 5 is a major E chord (E, G♯, B) – the raised leading tone typical of minor-key cadences. Result: **Am – G – F – E**. In D minor the same numerals give Dm – C – B♭ – A.

### Chord qualities in major and minor keys

DegreeMajor keyC majorNatural minorA minor1ICiAm2iiDmii°B°3iiiEmIIIC4IVFivDm5VGv (V in harmonic minor)Em (E)6viAmVIF7vii°B°VIIG

## Worked example

Inputs — Progression: I – V – vi – IV (pop “axis”); Key (tonic): C.

Results — **Chords = C – G – Am – F**; Roman numerals = I – V – vi – IV; Key and key signature = C major (no sharps or flats); Chords and their notes = # Numeral Chord Notes
─────────────────────────────
1 I C C, E, G
2 V G G, B, D
3 vi Am A, C, E
4 IV F F, A, C; Diatonic triads of the key = I C · ii Dm · iii Em · IV F · V G · vi Am · vii° B°; Diatonic seventh chords of the key = Imaj7 Cmaj7 · ii7 Dm7 · iii7 Em7 · IVmaj7 Fmaj7 · V7 G7 · vi7 Am7 · viiø7 Bø7.

## Key terms

- **Roman numeral analysis**: Naming chords by the scale degree of their root.
- **Diatonic chord**: A chord built only from notes of the key’s scale.
- **Cadence**: A chord progression that ends a phrase, such as V–I.
- **Borrowed chord**: A chord taken from the parallel major or minor key, such as ♭VII in a major key.

## FAQ

**What chords are in C major?**
C, Dm, Em, F, G, Am and B° (I ii iii IV V vi vii°); with sevenths Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bø7.

**What is the I–V–vi–IV progression in G?**
G – D – Em – C. It underlies hundreds of pop songs.

**What is a ii–V–I?**
The core cadence of jazz: Dm7 – G7 – Cmaj7 in C major. In minor it is iiø7 – V7 – i (Bø7 – E7 – Am7 in A minor).

**How do I write the 12-bar blues in A?**
A7 A7 A7 A7 | D7 D7 A7 A7 | E7 D7 A7 E7 – the I7, IV7 and V7 chords of A.

**Why is V major in a minor key?**
In natural minor the fifth chord is minor (v); composers raise the 7th degree (harmonic minor) to get a major V that pulls strongly to i. Write V for that chord.

**What does ♭VII mean?**
A major chord on the lowered seventh degree – B♭ in C major – borrowed from the parallel minor or the Mixolydian mode.

**What are the chords of the i–iv–v progression in F minor?**
Fm – B♭m – Cm; in A minor it is Am – Dm – Em.


## Sources

- [Open Music Theory (open textbook)](https://viva.pressbooks.pub/openmusictheory/)
- [musictheory.net – Lessons (notes, intervals, chords, keys)](https://www.musictheory.net/lessons)
- [Hooktheory – Chord progressions and Roman numerals](https://www.hooktheory.com/theorytab/common-chord-progressions)