How a capo works
A capo is a clamp that holds down all the strings at one fret. Each fret raises the pitch by one half step, so a capo on fret 2 makes the open strings sound a whole step higher. You keep fingering the same chord shapes, but every chord sounds higher. That lets you play a song in a hard key (like B♭ or F♯) using easy open shapes from G, C, D, A or E.
The formula
Shape key = song key − capo fret. Going the other way, sounding key = shape key + capo fret. A song in B♭ is three half steps above G, so putting the capo on fret 3 lets you play easy G shapes while it sounds in B♭.
Which chords are easy?
The friendliest guitar chords use open strings and no barre: C, A, G, E, D, Am, Em, Dm and their sevenths. That is why guitarists reach for the keys of G, C, D, A and E. The calculator scores each capo position by how many of the key's main chords fit those shapes, with extra weight on the tonic, the fourth and the fifth.
Capo chart: shapes and sounding keys
This table shows the major key you hear for each set of open shapes at each capo fret.
| Capo | C shapes | G shapes | D shapes | A shapes | E shapes |
|---|---|---|---|---|---|
| Fret 1 | D♭ | A♭ | E♭ | B♭ | F |
| Fret 2 | D | A | E | B | F♯ |
| Fret 3 | E♭ | B♭ | F | C | G |
| Fret 4 | E | B | F♯ | D♭ | A♭ |
| Fret 5 | F | C | G | D | A |
| Fret 6 | F♯ | D♭ | A♭ | E♭ | B♭ |
| Fret 7 | G | D | A | E | B |
For example, playing G shapes with the capo on fret 4 sounds in B major, and playing C shapes with the capo on fret 3 sounds in E♭ major.
Capo or transpose?
Both change the key. A capo does it on the guitar, so you keep the same fingerings and a bright, open sound. Transposing changes the written chords, which suits piano, voice or a group of mixed instruments. If you want the chords rewritten, use the chord transposer. To see what a chord is made of, try the chord finder.
Tips for playing with a capo
- Place the capo just behind the fret, not on top of it, to avoid buzzing.
- Retune after fitting it, because clamping can pull the strings a little sharp.
- Treat the capo as the new nut. Chord shapes are the same, and fret numbers count from the capo.
- Check your tab for a "Capo" line. The chords written are normally the shapes, not the sounding chords.
Frequently asked questions
What does a capo do?
A capo clamps across the neck and shortens the strings, raising every open string by one half step per fret. You keep playing the same easy shapes, but everything sounds higher, so you can match a singer's range or a song's key without barre chords.
How do I find which capo fret to use?
Take the key the song is really in and choose the capo fret that lets you play friendly shapes in G, C, D, A, E or their minors. The calculator above does this for you: enter the key and it ranks every fret.
What is the formula?
Shape key = song key minus the capo fret (in half steps). A song in B♭ with the capo on fret 3 means playing G shapes, because G plus three half steps is B♭.
Does a capo change the chords or just the key?
It changes what you hear, not what you finger. The shapes stay the same but every chord sounds higher by the number of frets. Use the Convert tab to see both versions.
What if the tab says "Capo 2"?
The chords written are the shapes to play with the capo on fret 2. To see the real chords that sound, choose "Shapes I play → real chords" and set the capo to 2.
Which capo positions are practical?
Frets 1 to 7 are the most common. Higher than that the frets get cramped and the guitar sounds thin, so the calculator only goes up to 9.