Guitar Chord Calculator is a handy reference of chords for 6-string guitar in standard tuning.

Eleven chord qualities at your fingertips for each of twelve root notes:

Major
minor (m)
Six (6)
Seven (7)
Nine (9)
minor 6 (m6)
minor 7 (m7)
Major 7 (maj7)
Sustained (sus4)
Diminished (dim)
Augmented (+)