RGB to CMYK color conversion

Enter red, green and blue color levels (0..255) and press the Convert button:

RGB to CMYK conversion formula

The R,G,B values are divided by 255 to change the range from 0..255 to 0..1:

R' = R/255

G' = G/255

B' = B/255

The black key (K) color is calculated from the red (R'), green (G') and blue (B') colors:

K = 1-max(R', G', B')

The cyan color (C) is calculated from the red (R') and black (K) colors:

C = (1-R'-K) / (1-K)

The magenta color (M) is calculated from the green (G') and black (K) colors:

M = (1-G'-K) / (1-K)

The yellow color (Y) is calculated from the blue (B') and black (K) colors:

Y = (1-B'-K) / (1-K)

Color name	(R,G,B)	Hex	(C,M,Y,K)
Black	(0,0,0)	#000000	(0,0,0,1)
White	(255,255,255)	#FFFFFF	(0,0,0,0)
Red	(255,0,0)	#FF0000	(0,1,1,0)
Green	(0,255,0)	#00FF00	(1,0,1,0)
Blue	(0,0,255)	#0000FF	(1,1,0,0)
Yellow	(255,255,0)	#FFFF00	(0,0,1,0)
Cyan	(0,255,255)	#00FFFF	(1,0,0,0)
Magenta	(255,0,255)	#FF00FF	(0,1,0,0)