This page collects the most common chords that begin with C, with clear diagrams for both guitar and piano. Use it as a quick reference to find the shape you need, from simple triads to extended and altered variations.
C
Chords that start with the letter
C major:
C - E - G
C minor:
C - E♭ - G
C7:
C - E - G - B♭
Cm7:
C - E♭ - G - B♭
Cmaj7:
C - E - G - B
Cdim:
C - E♭ - G♭
Cdim7:
C - E♭ - G♭ - A
Caug:
C - E - G#