The chart below listed the common chords that belong to the key of ​G Major. Chords in the circles are the principle chords in the key of​ G Major

Degree:	I	II	III	IV	V	VI	VII
Scale:	G	A	B	C	D	E	F#
Chords:	G	Am	Bm	C	D	Em	F#dim
Chords:	Gmaj7	Am7	Bm7	Cmaj7	D7	Em7	F#m7-5

Chords in the key of G

Scale:	G	A	B	C	D	E	F#
	G	A	B	C	D	E	F#
m	Gm	Am	Bm	Cm	Dm	Em	F#m
7	G7	A7	B7	C7	D7	E7	F#7
maj7	Gmaj7	Amaj7	Bmaj7	Cmaj7	Dmaj7	Emaj7	F#maj7
m7	Gm7	Am7	Bm7	Cm7	Dm7	Em7	F#m7
Add9	Gadd9	Aadd9	Badd9	Cadd9	Dadd9	Eadd9	F#add9
dim	Gdim	Adim	Bdim	Cdim	Ddim	Edim	F#dim
sus4	Gsus4	Asus4	Bsus4	Csus4	Dsus4	Esus4	F#sus4
sus2	Gsus2	Asus2	Bsus2	Csus2	Dsus2	Esus2	F#sus2
maj9	Gmaj9	Amaj9	Bmaj9	Cmaj9	Dmaj9	Emaj9	F#maj9
maj13	Gmaj13	Amaj13	Bmaj13	Cmaj13	Dmaj13	Emaj13	F#maj13
6	G6	A6	B6	C6	D6	E6	F#6
7sus4	G7sus4	A7sus4	B7sus4	C7sus4	D7sus4	E7sus4	F#7sus4
5	G5	A5	B5	C5	D5	E5	F#5

Common chord progression in the key of G

Degree	Chords
I - IV - V	G - C - D (D7)
I - VI - IV - V	G - Em - C - D (D7)
I - VI - II - V	G - Em - Am - D (D7)
I - III - IV - V	G - B7 - C - D (D7)
I - III - VI - V	G - Bm - Em - D (D7)
I - III - II - V	G - Bm - Am - D (D7)
I - II - IV - V	G - Am - C - D (D7)
I - II - VI - V	G - Am - Em - D (D7)
I - VI - II - V	G - Em - Am - D (D7)