Chord Progression Calculator
Build a progression by scale degree, inspect the harmony, hear it, transpose it, and copy or export the result.
Setup
Choose the harmonic contextProgression Builder
2–12 chordsQuick Analyze Existing Chords
Paste chord symbolsYour Progression
Session History
Accuracy: Notes, intervals, scale degrees, and transpositions are calculated from standard equal-tempered pitch-class relationships. Harmonic-function labels are contextual guides, not rules about what music must do.
Privacy: Calculations and playback happen in your browser. Session history uses sessionStorage and disappears when the browser session ends.
Troubleshooting: If you hear no audio, interact with the page once and check that your browser or device is not muted.
A Chord Progression Calculator helps you build, understand, and experiment with chord sequences without manually working out every scale degree or chord relationship. Choose a key and scale, select the chords you want, and the calculator can show the resulting chord names, Roman numerals, chord tones, harmonic roles, and other useful information for songwriting, arranging, practice, or music production.
Instead of treating chord progressions as isolated chord names, the calculator helps you see how each chord relates to the key. For example, a progression such as C – G – Am – F in C major can also be represented as I – V – vi – IV. That Roman numeral pattern can then be transferred to another key while keeping the same underlying harmonic structure.
If you already have a sequence of chords and want to understand what it is doing harmonically, you can also use the dedicated Chord Progression Analyzer for a more analysis-focused workflow.
How to Use the Chord Progression Calculator
Start by choosing the root key of your progression. Then select the scale or mode you want to work with, such as major, natural minor, Dorian, Mixolydian, or another available option.
Next, build your progression by choosing scale degrees or individual chords. Each position in the progression represents one harmonic step. Depending on the options available, you can also adjust chord qualities, extensions, inversions, and duration.
A typical workflow looks like this:
- Select a key, such as C major.
- Add several chords or scale degrees.
- Review the calculated chord names.
- Compare them with their Roman numeral equivalents.
- Inspect the notes and harmonic role of each chord.
- Play the progression to hear how it sounds.
- Transpose it if you want to test another key.
- Copy or export the result for use in your songwriting or DAW workflow.
If you want ideas before building your own sequence, the Random Chord Progression tool can provide a useful starting point that you can then modify here.
How the Calculator Determines Chords in a Key
A scale contains an ordered set of notes. Chords can be constructed from those notes by stacking intervals, most commonly thirds.
In a major key, the basic diatonic triad pattern is:
I – ii – iii – IV – V – vi – vii°
That means the first, fourth, and fifth chords are major; the second, third, and sixth are minor; and the seventh is diminished.
For example, the diatonic triads in C major are:
| Scale Degree | Roman Numeral | Chord |
|---|---|---|
| 1 | I | C major |
| 2 | ii | D minor |
| 3 | iii | E minor |
| 4 | IV | F major |
| 5 | V | G major |
| 6 | vi | A minor |
| 7 | vii° | B diminished |
The pattern changes when you choose a different scale or mode. This is why selecting the correct key and scale is important.
For a deeper look at how chords behave specifically in this key, see the C Major Chord Progressions guide.
Understanding Roman Numerals in Your Result
Roman numeral notation describes chords according to their position within a key rather than their absolute chord names.
For example:
C – G – Am – F
becomes:
I – V – vi – IV
in C major.
Uppercase numerals generally represent major chords, while lowercase numerals represent minor chords. Additional symbols can identify diminished chords, sevenths, inversions, and other harmonic details.
The advantage of Roman numerals is portability. The progression I – V – vi – IV can be moved from C major to G major:
G – D – Em – C
The chord names changed, but the relationships between the chords stayed the same.
If you regularly work with this system, the Roman Numeral Converter provides a dedicated way to convert between chord names and scale-degree notation. You can also learn the underlying notation in more depth in the guide to Roman Numeral Chords.
How to Read Your Chord Progression Results
The calculator can provide more information than the chord name alone.
Chord Name
This is the chord you would normally see on a chord sheet, such as C, Am, G7, or Fmaj7.
Scale Degree
The scale degree identifies where the chord is built within the selected key.
Roman Numeral
Roman numerals make it easier to recognize the progression pattern and transpose it into other keys.
Chord Notes
Chord tones show exactly which pitches make up the chord. A C major triad, for example, contains C, E, and G.
Harmonic Function
In conventional tonal harmony, chords can often be described by broad functions such as tonic, predominant, and dominant.
The tonic area tends to feel stable. Predominant chords can help move the harmony away from that stability, while dominant-function chords often create tension that can resolve toward the tonic.
These labels are useful analytical tools, but they are not rules that every song must follow.
Major and Minor Chord Progressions
Major and minor keys use different chord relationships, so a progression can change character significantly when moved between them.
A familiar major-key progression is:
I – V – vi – IV
A minor-key progression might use:
i – VI – III – VII
or:
i – iv – V – i
depending on the musical context and the form of the minor scale being used.
Minor-key harmony can involve natural minor, harmonic minor, melodic minor, modal borrowing, or chromatic alterations, which means not every useful progression will fit into a single fixed diatonic pattern.
For more examples, compare the guides to Major Key Chord Progressions and Minor Key Chord Progressions.
Choosing the Next Chord
There is no single correct chord that must follow another chord.
A calculator can identify chords that belong to the selected key and show common harmonic relationships, but songwriting is not determined by a fixed formula. Repetition, melody, bass movement, rhythm, voice leading, genre conventions, and intentional tension can all influence which chord sounds right next.
Common patterns are still useful starting points. Progressions such as I–IV–V, I–V–vi–IV, ii–V–I, and vi–IV–I–V appear frequently because their harmonic movement is easy to recognize and adapt.
You can explore more established patterns in the guide to Common Chord Progressions and then modify them rather than treating them as fixed templates.
Transposing a Chord Progression
Transposition moves a progression to another key while preserving its interval relationships.
Suppose you have:
C – G – Am – F
and want to move the progression from C major to D major.
The equivalent progression becomes:
D – A – Bm – G
The Roman numerals remain:
I – V – vi – IV
This is especially useful when adjusting a song for a singer’s range, changing guitar-friendly chord shapes, arranging music for another instrument, or trying different tonal centers.
For a focused transposition workflow, use the Chord Transposer.
Using the Calculator for Songwriting and Production
A chord progression calculator can be useful at several stages of music creation.
Songwriters can test different scale degrees before committing to a verse or chorus progression. Guitarists and pianists can examine chord tones and compare alternative inversions. Producers can audition different progressions and then transfer the result into a DAW or MIDI-based workflow.
The calculator can also help when studying existing music. Converting chord names into Roman numerals makes it easier to compare songs written in different keys and recognize recurring harmonic structures.
If you want to move beyond choosing chords and learn how to design stronger sequences intentionally, read How to Write Chord Progressions.
Accuracy and Limitations
The calculator can accurately derive chords from defined scale structures and display their pitch content and scale-degree relationships. However, harmonic interpretation can become more subjective when a progression contains chromatic chords, borrowed chords, secondary dominants, modal interchange, key changes, or ambiguous tonal centers.
A chord outside the selected scale is not automatically wrong. Non-diatonic harmony is common in pop, jazz, rock, gospel, film music, and many other styles.
Similarly, a progression that follows standard theory is not automatically musically better than one that does not. The calculator should be used as a theory and experimentation tool rather than a rulebook.
Advanced writers can explore alternatives through techniques such as Chord Substitution once the basic progression is established.
Privacy and Browser Processing
The calculator is designed to perform its interactive calculations directly in your browser. Selecting keys, changing chords, transposing a progression, or previewing calculated results does not require you to submit personal information simply to use the core calculator.
Any temporary progression history stored for convenience should be treated as browser-session data rather than a permanent user account or cloud project unless a separate feature explicitly states otherwise.
Frequently Asked Questions
What is a chord progression calculator?
A chord progression calculator is a music-theory tool that helps build or interpret sequences of chords according to a selected key, scale, and harmonic relationships.
What chords belong to a major key?
The basic diatonic triad pattern in a major scale is I major, ii minor, iii minor, IV major, V major, vi minor, and vii diminished.
What does I–V–vi–IV mean?
It describes chords built on the first, fifth, sixth, and fourth scale degrees. In C major, that becomes C–G–Am–F.
Do all chords in a progression need to be in the same key?
No. Songs frequently use borrowed chords, secondary dominants, chromatic chords, modal interchange, and key changes.
Can I transpose the same progression to another key?
Yes. Roman numeral relationships can remain unchanged while the actual chord names move to fit the new key.
What is the best chord progression?
There is no universally best progression. The right sequence depends on melody, rhythm, genre, arrangement, emotional direction, and the musical effect you want.
Can the calculator tell me which chord should come next?
It can suggest harmonically related or commonly used choices, but those suggestions are creative options rather than rules.
Why use Roman numerals instead of chord names?
Roman numerals reveal how chords function relative to a key. This makes it easier to analyze patterns and reuse the same progression in different keys.