RGB to CMYK color conversion calculator

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

Red color (R):
Green color (G):
Blue color (B):
	Convert Reset Swap
Cyan color (C):	%
Magenta color (M):	%
Yellow color (Y):	%
Black key color (K):	%
Hex:
Color preview:

RGB to CMYK conversion formula and chart

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)

RGB to CMYK table

Color	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)