CMYK to RGB Converter

Convert CMYK print color values to RGB screen color values and vice versa.

Tested tool guide Tested browser tools Checked August 16, 2026

What CMYK to RGB Converter does, with a checked example

CMYK to RGB Converter translates cyan, magenta, yellow, and key black percentages into red, green, and blue channel values, and can reverse the calculation. It uses direct arithmetic relationships between the four CMYK components and the three RGB channels. The main surprise is that the result is a numerical counterpart, not a color-managed print proof. Actual appearance can change with the RGB profile, CMYK profile, ink, paper, press, display, and viewing conditions.

Worked example

A concrete input and expected output from the current implementation.

Input

C: 0%
M: 100%
Y: 100%
K: 0%

Expected output

R: 255
G: 0
B: 0

With 0% black and 0% cyan, red remains at 255. The 100% magenta and yellow components reduce green and blue respectively to 0, producing RGB 255, 0, 0.

How the result is produced

CMYK to RGB

CMYK percentages are treated as fractions from 0 to 1. Red is 255 x (1 - C) x (1 - K), green uses M in place of C, and blue uses Y. The resulting RGB channels are reported on the 0 to 255 scale; fractional channel results may require rounding.

RGB to CMYK

For the reverse direction, each RGB channel is divided by 255. K is 1 minus the largest normalized RGB channel. When K is below 1, C, M, and Y are found by removing K from the remaining channel deficits. RGB black is handled as C=0%, M=0%, Y=0%, K=100%.

Good uses

Turn a printer-supplied CMYK swatch into an RGB starting point for a screen mockup.
Convert RGB brand colors into preliminary CMYK percentages before preparing print artwork.
Compare legacy CMYK palette entries with the RGB channel values needed by a digital design application.

Limits and checks

Treat the result as a numerical conversion, not a press proof; CMYK appearance depends on the output profile, ink, paper, and printing process.
Enter CMYK components as 0 to 100 percentages and RGB components on the 0 to 255 scale; confusing these scales produces a different color.
An RGB-to-CMYK result cannot recover a unique original ink separation because multiple CMYK combinations can map to the same RGB triplet.

Common questions

Will the converted RGB color exactly match the printed CMYK color?

No. The RGB triplet is a useful nominal screen counterpart, but a printed CMYK sample is device-dependent. A dependable match needs appropriate ICC profiles, calibrated viewing conditions, and usually a soft proof or physical proof. This converter alone cannot account for those production variables.

Why can a CMYK to RGB to CMYK round trip change the values?

CMYK has four components while RGB has three, so multiple CMYK recipes can collapse to one RGB triplet. For example, CMYK 100%, 100%, 100%, 0% converts to RGB 0, 0, 0. Reversing that black gives CMYK 0%, 0%, 0%, 100% under the direct conversion rule.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.