I-IV-V in Every Key

I-IV-V in all keys
Key	I	IV	V
Key of C	C	F	G
Key of Db	Db	Gb	Ab
Key of D	D	G	A
Key of Eb	Eb	Ab	Bb
Key of E	E	A	B
Key of F	F	Bb	C
Key of Gb	Gb	Cb	Db
Key of G	G	C	D
Key of Ab	Ab	Db	Eb
Key of A	A	D	E
Key of Bb	Bb	Eb	F
Key of B	B	E	F#

The I, IV and V chords in any key are the major chords built on the 1st, 4th and 5th notes of the major scale in that key. In the event that you don't know all of your major scales, here's a chart with the I, IV and V chords in every key.