In the interest of wanting to find the best capo to use when transposing songs to play on guitar, I came across a useful webpage called Capo Calculator. While this page is really good at what it does, it is limited in that it’s impossible to use on a mobile device. So I decided to try and create my own version of it. That’s how capo-calc was created.

It’s a small Python script that basically takes in the chords you’re wanting to find the best capo for, and returns back the best three options based on the “weights” of each chord. Open chords are the easiest to play and thus are favored more heavily than barr chords, which require a lot of strength to play.

Here is an example of it in action:

$ capo-calc A Gm C

Input:   A, Gm, C
Capo  5: E, Dm, G
Capo  2: G, Fm, Bb
Capo  3: Gb, Em, A

It’s possible I will take this and create a small webpage out of it in the future, and finally achieve the goal of being able to do it from my phone, but for now this is good enough. I’ll update this page if I ever get around to making it. Then again, I have been using Brython a lot recently - more on that to come.

The source code is available on my GitHub here and is under an MIT license.