CMYK to RGB Converter
CMYK is the subtractive color model used for printing: cyan, magenta, yellow, and key (black) inks absorb light, while RGB is the additive model screens use to emit it. To preview a print color on screen, you convert the four CMYK percentages into red, green, and blue values. Enter the four channels as percentages (0 to 100) and this converter returns the RGB values and the hex code. The formula is the standard device-independent conversion; an exact match needs a color-managed ICC profile.
CMYK to RGB formula
c, m, y, k = each percentage / 100
Red = 255 * (1 - c) * (1 - k)
Green = 255 * (1 - m) * (1 - k)
Blue = 255 * (1 - y) * (1 - k)
Hex = each RGB channel as two hex digits, prefixed with #
The key (black) channel scales all three colors toward zero. At k equal to 1 the result is black regardless of the other channels.
Color model context
- CMYK is subtractive (inks absorb light); RGB is additive (screens emit light).
- K (key) is the black channel, giving deep blacks economically.
- CMYK 0, 100, 100, 0 maps to pure red (255, 0, 0) by this formula.
- An exact print match requires an ICC color profile for the device and paper.
- This standard formula is device-independent and a close visual approximation.
CMYK to RGB converter: frequently asked questions
How do you convert CMYK to RGB?
Express each CMYK channel as a fraction from 0 to 1. Then red equals 255 times (1 minus cyan) times (1 minus key), green equals 255 times (1 minus magenta) times (1 minus key), and blue equals 255 times (1 minus yellow) times (1 minus key). The key (black) channel darkens all three.
What does the K in CMYK stand for?
K stands for key, the black ink channel. It is called key because in printing the black plate carries the key detail and alignment. Adding K produces deep blacks more economically than overlaying full cyan, magenta, and yellow.
Why is this only an approximation?
CMYK is a subtractive model for inks on paper, while RGB is additive light on a screen. The exact mapping depends on the printer, inks, paper, and an ICC color profile. This calculator uses the standard device-independent formula, which is a close approximation but not a color-managed match.
What CMYK values produce pure red on screen?
Cyan 0 percent, magenta 100 percent, yellow 100 percent, key 0 percent gives red 255, green 0, blue 0 by this formula. Magenta and yellow together subtract green and blue light, leaving red.
How is the hex code produced?
Each computed RGB channel (0 to 255) is converted to a two-digit hexadecimal value and concatenated with a leading hash. RGB 255, 0, 0 becomes #FF0000. This is the same hex notation used in HTML and CSS.
Official sources
- W3C: CSS Color Module Level 3 (RGB and device color).
- International Commission on Illumination: CIE colorimetry reference.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.