What is the CMYK to RGB formula?

Each RGB channel equals 255 times (1 minus the ink) times (1 minus black). For example R = 255 * (1 - C/100) * (1 - K/100). This is the standard naive conversion used when no ICC colour profile is involved.

Will the screen colour exactly match my print?

Not always. CMYK is device and paper dependent and uses ICC profiles for accurate proofing. This tool gives the standard mathematical conversion, which is ideal for web mockups and quick previews.

Is anything sent to a server?

No. The conversion runs entirely in your browser — nothing is uploaded or logged.

CMYK to RGB Converter

Convert print CMYK percentages into screen RGB values.

CMYK to RGB converter

Enter cyan, magenta, yellow and key (black) ink percentages and get the equivalent RGB value instantly, with a live colour swatch.

CMYK describes print inks, while RGB describes screen light. This converter applies the standard formula so you can preview a print colour on screen — all in your browser, nothing uploaded.