Guitar Capo Calculator

What a capo actually does

A capo shortens every string at the same fret, so everything you play sounds higher by that many semitones. Nothing else changes - the shapes under your fingers are identical, the chord names that come out are not. A capo at the second fret turns a C shape into a sounding D, a G shape into an A, and so on.

That is the entire mechanism, and it is why a capo is so useful: it lets you play a song in whatever key the singer needs while still using the open shapes that sound good on a guitar.

Both directions

The first question is "I am playing these shapes with a capo here - what am I actually playing?" That matters when you are writing chords down for someone else, or working out whether you can play along with a recording.

The second is the more common one: "This song is in E flat and I cannot play E flat." E flat with open shapes is unpleasant. With a capo at the third fret it is a C shape, which is easy. The calculator lists every capo position that turns your wanted key into something playable.

Why the key changes but the chords do not

This is the bit that confuses people. With a capo at fret 3, you play a C shape and it sounds as E flat. Somebody reading over your shoulder sees you playing C. Both are true: the shape is C, the sound is E flat. When you tell another guitarist what to play, give them the shape and the capo position. When you tell a pianist or a singer, give them the sounding key.

Where to put it

Just behind the fret, not on top of it and not halfway between - the same place your finger goes. Too far back and strings buzz; on top of the fret and they choke. Tighten only as much as it needs: an over-tightened capo pulls the strings sharp, which is why a guitar that was in tune can sound wrong the moment the capo goes on. Retune after fitting it.

Related tools

Chord transposer, chord finder, guitar tuner.