Chord: -
Formula: -
Chord builder
Choose a root and chord type, then add sevenths, extensions, added tones or alterations as needed.
The Guitar Chord Finder lets you identify chords from notes on the fretboard, explore the notes that make up a chord, and find playable chord voicings. Rather than relying only on memorised chord diagrams, you can examine the intervals behind a chord and see how the same notes appear in different positions.
If you have found an unfamiliar chord shape, use the Analyser to identify it. Select the notes you are playing on the fretboard, then analyse your selection to find matching chord names.
For example, E, G♯ and B form an E major chord: E is the root (1), G♯ is the major third (3), and B is the perfect fifth (5). Together, they produce the major-triad formula 1–3–5.
The same notes can appear in different octaves and fretboard positions without changing the basic chord identity. Their arrangement affects the voicing, but not the underlying major triad. To understand why these intervals produce a major chord, read Introduction to Triads.
Arpeggio mode shows where the notes of a selected chord appear across the guitar neck. Choose a root note and chord type to display its chord tones across the strings and frets.
For example, selecting A minor displays A, C and E, which form the minor-triad formula 1–♭3–5. Use these note locations to practise arpeggios, connect chord shapes, or identify chord tones when improvising. If the interval numbers are unfamiliar, start with Interval Basics.
Voicings mode lets you browse different ways of playing a selected chord. Two chord shapes can contain the same essential notes but arrange them differently across the strings.
A C major chord contains C, E and G. One voicing might place C in the bass, while another places E or G underneath the remaining chord tones. These arrangements change the chord's sound and how easily it connects to surrounding chords.
The tool includes common chord shapes and selected inversions rather than every theoretically possible fingering. You can also explore seventh chords and more complex structures using the chord controls. For more on their construction, see Seventh Chords.
Yes. Some note collections have several valid interpretations, particularly when the root is unclear or important chord tones are missing. The surrounding harmony and bass note help determine the most appropriate name.
The same chord tones appear in multiple places on the fretboard. You can combine them in different positions, double particular notes, or change which note is lowest. These arrangements are called voicings.
Reference library
A quick-reference collection of common chord structures and their interval formulas.
The Chord Type menu contains the main basic chord structures as presets, so these do not need to be built manually.
The formulas below cover the most common chords. Many more extended, altered and combined structures are possible, but these are the ones you are most likely to encounter.
Preset chord types
6th chords
7th chords
6/9 and 9th chords
11th and 13th chords
Add chords
For other chords, choose the appropriate basic chord type first, then use the Seventh, Extension, Add tone and Alteration controls.
These are only common examples. The tool can build many more combinations using the additional controls.
Common altered dominant chords
Altered dominant chords keep the major 3rd and minor 7th of a dominant chord while changing one or more colour tones.
Chord labels can look complicated at first, but they are just a compact way of describing which notes are in the chord. The tool uses these labels because they are the common language musicians use to describe harmony.
Before you go any further, one important point: chord names only make sense once you understand intervals. Every chord is defined by the distances between notes, and the label is simply a shorthand for those distances. Read more below to find out more.
1What is a root?
Every chord starts from a root note.
The root is the note the chord is named after, and it acts as the reference point for everything else in the chord. When you see a chord label like C, Am, or G7, the letter at the beginning tells you the root.
For example:
Important clarification:
The root is not defined by pitch height or voicing. It doesn’t matter whether the root is the lowest note you play or where it appears on your instrument. The root is a theoretical reference, not necessarily the bass note.
All other notes in a chord are described by their intervallic distance from the root.
2What are intervals?
If the root is the starting point, an interval is the distance from that note to another note. Think of it as a measurement, like inches or centimetres, but for sound. In music, we describe this distance using two pieces of information: a distance (number) and a quality.
The distance
The distance, formally called the interval number, tells us how far apart two notes are in terms of letter names.
To find it, start on the root and count up through the musical alphabet until you reach the second note. Include both notes in your count.
For example:
| From | Letter count | Interval |
|---|---|---|
| C to D | C–D | 2nd |
| C to E | C–D–E | 3rd |
| C to F | C–D–E–F | 4th |
This counting is alphabetical, so sharps and flats do not change the interval number.
| Example | Still a | Because it spans |
|---|---|---|
| C to E♭ | 3rd | C to E |
| C to F♯ | 4th | C to F |
At this stage, we only care about the letter distance, not the exact number of semitones.
The quality
Once we know the distance (number), we also describe the interval’s quality. Quality tells us the exact size in semitones.
| Quality | Description |
|---|---|
| Perfect | Used for unisons, 4ths, 5ths, and octaves in their unaltered form |
| Major | The larger standard form of a 2nd, 3rd, 6th, or 7th |
| Minor | One semitone smaller than the corresponding major interval |
| Augmented | One semitone larger than a perfect or major interval; adds tension |
| Diminished | One semitone smaller than a perfect or minor interval; adds tension |
Only 2nds, 3rds, 6ths, and 7ths can be major or minor.
Unison, 4th, 5th, and octave belong to the perfect group.
How intervals change
After learning interval number and quality, it helps to know how intervals change when we raise or lower them by semitones:
Intervals can also be raised or lowered by two semitones, creating more extreme augmented or diminished versions. For now, understanding the one-semitone changes above is enough.
3C chromatic reference (from root C)
In the previous section, we learned that an interval is the measured distance between two notes, and that in the context of chords these distances are described relative to the root note.
This section shows the next step: every possible interval you can form from a single reference note.
We use the chromatic scale because it contains all 12 pitches in the standard 12-tone system. That allows us to map:
C Chromatic Scale (intervals from C)
Treat C as 1 (0 semitones). Moving to the right, each step rises by one semitone, showing how each pitch is named relative to the root.
This table shows one practical label for each of the 12 pitch classes relative to C. It is not a complete list of theoretical spellings: the same sounding pitch can have different interval names depending on its harmonic role, such as C♯ as ♯1 or D♭ as ♭2.
Chromatic Interval Names (relative to C)
| Interval | Name |
|---|---|
| 1 | Root / Tonic |
| ♭2 | Minor 2nd |
| 2 | Major 2nd |
| ♭3 | Minor 3rd |
| 3 | Major 3rd |
| 4 | Perfect 4th |
| Interval | Name |
|---|---|
| ♯4 / ♭5 | Augmented 4th / Diminished 5th |
| 5 | Perfect 5th |
| ♭6 | Minor 6th |
| 6 | Major 6th |
| ♭7 | Minor 7th |
| 7 | Major 7th |
C Major Scale Reference
For comparison, here is the C major scale, which selects seven of those twelve possible intervals.
C Major Scale (intervals from C)
The chromatic scale shows all possible interval options.
The major scale shows which of those intervals the major scale uses.
4Let’s make our first chord! Triads explained
Now that we understand how intervals are named, we can look at how different combinations of intervals create different chords.
The most basic chord structures used here contain three notes. Major, minor, diminished and augmented triads contain a root, a type of third, and a type of fifth. Suspended three-note chords replace the third with a 2nd or 4th.
Major, minor, diminished and augmented triads use tertian harmony: they can be understood as stacked thirds. Suspended chords are included alongside them in this tool for convenience, but they are not built as an ordinary stack of thirds because the third has been replaced.
Example in C major
C major triad:
C major scale:
Pick 1 – 3 – 5 from the scale.
The above is an example of a major triad. The intervals are the same for all major triads regardless of the root.
Example in C minor
C minor triad:
C minor scale:
Pick 1-♭3-5 from the scale.
Six basic chord types
The six structures below are the basic chord formulas used as starting points throughout the tool.
Major triad
Minor triad
Diminished triad
Augmented triad
Sus2 triad
Sus4 triad
5Seventh chords
Stacked thirds revisited
Earlier, we saw that triads are built by stacking thirds. This means starting from a root, adding a note a third above it, and then adding another third above that.
We can continue this same process. If we stack one more third on top of a triad, we get a seventh chord. Seventh chords add a new note that is a seventh above the root, creating a richer sound than a basic triad.
C major scale
To see this visually, here is the C major scale again:
For a major 7th chord, take 1 – 3 – 5 – 7.
Creating seventh chords
If you remember from the interval section, the 2nd, 3rd, 6th, and 7th can be major or minor. This means the 7th above a root can either be:
* There is also a ♭♭7. This special case is used with diminished triads and is explained further down. For now, you can disregard it.
What this means is we can take any of our base triads and create combinations of triads with either of the 7th intervals. These give us unique chord types.
Seventh chord = Triad + 7 or Triad + ♭7
By combining a triad with either a major 7th or a minor 7th, we get different 7th chord variants.
Major/minor triad + 7th combinations
Using C as the root, below are the four base 7th-chord combinations: a major triad + 7, a major triad + ♭7, a minor triad + ♭7, and a minor triad + 7.
Major 7th (maj7)
Dominant 7th (7)
Minor 7th (m7)
Minor-major 7th (mMaj7)
Other less common 7th chords
There are other less commonly used 7th chords. These are made by taking other triad types (suspended, augmented, diminished, or altered-fifth variants) and adding either a major 7th (7) or a minor 7th (♭7).
These chords are less frequently used but add colour and tension to music.
Formulas for less common 7th chords:
Half-diminished 7th (m7♭5)
Dominant 7th flat 5 (7♭5)
Diminished-major 7th (dimMaj7)
Minor 7th sharp 5 (m7♯5)
Suspended 2nd 7th (sus2 7)
Suspended 4th 7th (sus4 7)
Augmented 7th (aug7)
Augmented-major 7th (augMaj7)
Fully diminished 7th chord
The fully diminished 7th chord is the most tense and dissonant 7th chord. It is built from a diminished triad with a diminished 7th on top.
Structure
Fully diminished 7th (dim7)
Why we use a ♭♭7
The double flat looks odd at first, but it is just a naming rule so the chord stays consistent.
A diminished 7th chord is built by stacking minor thirds on top of a diminished triad. If we measure the top note from the root:
That top note is still functioning as “the 7th” of the chord, so we keep the number 7 in the label. Writing it as ♭♭7 tells you it is a seventh that has been lowered twice, rather than switching to a different interval name.
It also keeps the chord’s shape consistent on paper, because every step stays a minor third:
One extra thing that helps: on a guitar (and a piano), B♭♭ sounds the same as A. But we still write B♭♭ because it shows the chord is built as stacked thirds, and that is what makes diminished 7th chords sound tense and symmetrical.
6Extended chords (9ths, 11ths and 13ths)
We’ve already seen that triads are built by stacking two thirds: root → third → fifth.
Seventh chords extend this idea by adding one more third on top of the triad.
Extended chords are the next step in the same process: we keep stacking thirds above the seventh to add more notes.
If we continue this stacking, we get the sequence: 1 – 3 – 5 – 7 – 9 – 11 – 13.
This shows that the principle is the same at every level: triads → seventh chords → extended chords.
When we add notes beyond the seventh, the numbers 9, 11, and 13 can seem confusing at first.
The key is to remember Section 2: intervals are counted alphabetically from the root.
So extended chord numbers are not arbitrary. They are the next stacked intervals above the seventh, following the same counting system.
C major example – two octaves
Altered notes in extended chords
Extended chords can include notes that are raised (♯) or lowered (♭).
If we alter one upper note, we usually notate that interval as altered rather than renaming the chord completely. This adds colour or tension while keeping the base structure.
Required intervals in extended chords
In an extended chord symbol, each higher extension implies an underlying seventh-chord structure.
In practice, guitar voicings commonly omit the perfect 5th and may omit lower extensions. The root, quality-defining third or suspension, required 7th, alterations, and explicitly named upper colour remain the important identity tones in this tool.
Practical limitations on guitar
Playing every note in extended chords on guitar is often impossible. We have four fingers and one thumb, and only six strings, so there is a limit to how many notes can fit in one voicing.
Because of this, non-vital intervals are often left out. For example, in an 11th chord a guitarist may keep the root, third, seventh, and 11th, while omitting notes like the fifth or 9th to make the shape playable.
7Add chords and 6th chords
Add chords are a simple way to get a richer sound without moving into full extended harmony. The idea is: start with a normal major or minor triad, then add one extra note. Importantly, you keep the third in place, so the chord still clearly sounds major or minor.
Sixth chords use a related structure: a major or minor triad with a 6th added. By convention, they are labelled 6 or m6 rather than “add6”.
What "add" means
Begin with a triad:
Then add one extra scale degree:
Where 6th chords fit
A 6th chord is a triad plus a 6th:
You will sometimes see the name "add6", but most guitarists and theory resources just call it "6" or "m6". The important part for this tool is the structure: it is still a triad with one added note, and no 7th implied.
6th chords vs 13th chords
This is the same "same note, different meaning" problem as add9 vs 9:
So:
Add9 vs add2 (and add11 vs add4)
On paper, 2 and 9 are the same note in different octaves. The same is true for 4 and 11, and for 6 and 13.
In real guitar voicings, the "add9" label is often used even if the added note is close to the triad, because it describes the colour more than the exact octave.
Add chords vs extended chords
A practical rule:
Add chords vs suspended chords
Suspended chords replace the third, add chords keep it:
That is why add chords feel like a normal major or minor chord with extra sparkle, while sus chords feel more open and unresolved.
Why might a chord be missing?
If a chord selection does not return a shape, it does not necessarily mean that the chord does not exist or that the combination is theoretically impossible.
Usually, it means one of two things: either the chord contains too many essential notes to fit into a sensible six-string voicing, or I have not yet added a version that I consider worth recommending.
That is deliberate. I would rather show no result than quietly remove an important note just to make a shape fit, or fill the tool with awkward fingerings simply because they are technically possible.
1How the chord library was built
I began by manually entering the standard guitar voicings and common variations to establish the core catalogue.
The challenge was not working out how to play the chords. Any unfamiliar voicing can be derived from the chord’s interval structure and the fretboard. The real problem was scale.
Once the tool allows added notes, altered notes, ninths, elevenths, thirteenths, suspensions and altered fifths to be combined freely, the number of possible interval sets becomes very large. Manually entering and curating suitable voicings for every one of those combinations would be extremely time-consuming, so I built a system that could use the chord formula and fretboard note map to search for candidate shapes automatically.
2Why I moved away from automatic generation
From a theory point of view, the generator worked. It could identify combinations of frets that contained the required notes for a selected chord. The problem was that finding the correct notes is not the same thing as finding a good guitar voicing.
The generator could return excessive stretches, awkward string combinations, impractical barres or shapes that were technically playable but offered no real advantage over better alternatives.
I initially tried to solve this with rules about fret span, finger placement, barres, string spacing and other signs that a voicing would be uncomfortable or unrealistic. That worked to a point, but every general rule created an edge case where a good shape was rejected. The exceptions then created more edge cases, and the rule set became increasingly complicated.
The underlying problem is that guitar playability is difficult to reduce to a simple mathematical test. Two shapes with a similar fret span can feel completely different depending on the strings used, which fingers naturally fall into position, whether a barre is practical, and how the hand approaches the shape. The generator also produced too many slight variations of the same basic idea.
Eventually, maintaining the heuristic system made less sense than curating the results directly. The live tool no longer generates arbitrary chord shapes as you use it. Instead, it returns voicings from a curated catalogue. The theory and fretboard systems still resolve the selected chord, understand its interval structure, transpose movable shapes correctly and check that a voicing matches the requested harmony. The final decision about which shapes are worth showing, however, is curated.
I would rather show a handful of useful voicings than dozens of mathematically valid alternatives that add nothing.
3What makes a shape acceptable?
A voicing has to preserve the notes that define the chord. A major chord needs its major third. A minor chord needs its minor third. A suspended chord needs its suspension.
If a seventh, altered fifth, altered ninth or another defining alteration has been selected, that note also needs to be present. The voicing must not introduce notes that do not belong to the selected chord.
With larger extended chords, some notes can be omitted without changing the essential identity of the harmony. The ordinary perfect fifth is normally the first note that can be left out. In many extended chords it adds less harmonic information than the third, seventh or upper extension.
An altered fifth is different. A flattened or sharpened fifth changes the character of the chord and therefore has to remain. Lower implied extensions can also sometimes be omitted: an 11th chord may not need the 9th in every practical guitar voicing, and a 13th chord may omit the 9th or 11th where necessary. Explicitly selected alterations and additions are treated differently. If you specifically ask for a note such as ♭9, ♯11 or ♭13, the voicing should contain it.
4Why some chords cannot be shown
There is also a simple physical limit: a standard guitar has six strings. If a particular chord selection contains seven different notes and all seven are essential, there is no way to play all of them simultaneously on a standard six-string guitar.
Some six-note chords are also difficult to represent well because every string has to contribute one of the required notes while still producing a sensible fingering. In those cases, the absence of a shape is intentional rather than an error.
5The numbers, if you are curious
The numbers get big very quickly. Once you fix a root note, each of the other 11 notes in the chromatic scale can either be included or left out. That gives 211 = 2,048 possible note combinations containing the root.
Of course, that includes everything from a single note right through to all 12 notes of the chromatic scale, so it is not a useful count of actual guitar chords. The interesting part is how quickly the possibilities multiply once you start combining normal chord structures with sevenths, extensions, suspensions and alterations.
The tool currently resolves its available controls into 1,158 distinct interval families before a root note is chosen. Some of those describe more notes on paper than a six-string guitar can physically play at once, but that does not automatically make the chord unplayable. In many extended chords, some implied tones can legitimately be left out.
What matters is not simply how many notes appear in the full formula, but how many of them are essential to that particular chord. If seven notes are genuinely required, it cannot be played in full on six strings. If one or more are optional, a perfectly valid six-string voicing may still be possible.
6Movable shapes, open chords and inversions
Many shapes in the catalogue are movable. That means the fingering can be shifted up or down the neck to produce the same chord structure from another root. The catalogue also contains open-position shapes where they provide useful alternatives. These are naturally more key-specific because the open strings remain fixed pitches.
For inversions, I have deliberately kept the system fairly simple. Where practical, the basic chord shapes include first and second inversions, and most seventh chords also include a third inversion.
In theory, larger chords can continue much further. A five-note chord can have a fourth inversion, a six-note chord can have a fifth inversion, and so on. Those inversions are theoretically valid, but they quickly become much less useful in a general guitar chord tool.
Once extensions or alterations start appearing in the bass, the harmonic effect can change quite dramatically. A 9th, 11th, 13th or altered tone underneath the rest of the chord can make the voicing behave more like a slash chord, suggest a different root, or change how the chord functions within a progression. Enharmonic spelling can make this even more ambiguous.
So although fourth, fifth and higher inversions are perfectly possible in theory, including every one of them would introduce a lot of additional complexity for relatively little practical benefit. The aim is not to catalogue every possible rearrangement of every chord tone. It is to include the inversions that are most useful for understanding and playing the chord without turning the inversion system into another layer of harmonic ambiguity.
7What is still being added?
The main gaps are now among the more heavily altered and extended interval combinations. I am working through those progressively and adding voicings where there is something genuinely useful to add.
Some combinations will probably remain unsupported deliberately. Just because a set of controls can produce a mathematically valid interval combination does not mean that combination deserves a permanent place in a guitar chord library.
The aim is not to collect every theoretical combination possible. It is to build a comprehensive catalogue of guitar voicings that are correct, useful and worth playing.
If you find a chord that does not currently return a shape and think it should, let me know. I can check that exact interval set and add suitable voicings where appropriate.