Capo Transpose Calculator
A capo raises every open-string pitch by one semitone for each fret it sits behind, so the easy shapes you finger above it sound in a higher key. This calculator takes the capo fret and the root of the chord shape you are playing (as a semitone number, where C is 0) and returns the sounding root, the total semitone shift, and the exact frequency multiplier. Guitarists use it to match a singer's range, line up with a recording, or keep comfortable open voicings while playing in a sharp or flat key. The result is the equal-temperament transposition that the capo produces.
Capo transpose formula
Semitone shift = capo fret
Sounding root = (shape root + capo fret) modulo 12
Frequency multiplier = 2^(capo fret / 12)
Note name = lookup of sounding root in the chromatic scale
Roots are numbered C=0 up to B=11. The modulo 12 wraps the count back into one octave, so the name is correct regardless of how high the capo sits.
Capo context
- Each fret of capo raises the sounding pitch by exactly one semitone.
- A capo on 2 makes a G shape sound in A; a capo on 3 makes a C shape sound in E flat.
- Higher capo positions brighten the tone because the vibrating strings are shorter.
- Use a capo to fit a song to a vocal range without relearning shapes.
- The frequency multiplier shows how much higher every open string rings.
Capo transpose: frequently asked questions
How does a capo change the key?
A capo clamps across a fret and raises the pitch of every open string by one semitone per fret. A chord shape you play above the capo sounds that many semitones higher than it would with no capo. A capo on the second fret makes a shape sound two semitones, a whole tone, higher.
If I play a C shape with a capo on 3, what sounds?
Three frets up from C is E flat (or D sharp). So a C-shaped chord with the capo on the third fret produces an E flat chord. This calculator returns the semitone shift; add it to the root of your shape, wrapping around after twelve, to name the sounding chord.
Why use a capo instead of barre chords?
A capo lets you keep easy open-string shapes while raising the key to suit a singer's range or another instrument. It also changes the timbre, since shorter vibrating strings sound brighter. Many players use a capo to match a recording or to find a more comfortable voicing.
How much higher in frequency is each fret?
Each fret raises the frequency by the twelfth root of two, about 1.0595 times. So a capo on the fifth fret multiplies every open-string frequency by two raised to five over twelve, roughly 1.335 times, between a perfect fourth and a tritone above.
Does the capo position change the chord names I read?
No. You still read and finger the same shapes; only the sounding key changes. Capo charts work by letting you play in an easy shape key while the audience hears the transposed key. This tool tells you exactly how many semitones the transposition is.
Official sources
- UNSW School of Physics: Note names, MIDI numbers and frequencies.
- UNSW School of Physics: Strings, standing waves and harmonics.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.