How is CMYK converted to RGB and HEX?

The tool uses the standard device-independent formula: R = 255 × (1 − C) × (1 − K), and likewise for green from magenta and blue from yellow, where C, M, Y and K are fractions from 0 to 1. The RGB result is then written as a HEX code.

Will the HEX colour exactly match my print?

Not exactly. CMYK is a device-dependent print model — true output depends on the paper, ink and ICC colour profile of your printer. This conversion gives the standard on-screen approximation, which is ideal for previewing print colours on the web.

What does the K channel do?

K is the key (black) channel. Increasing K darkens the colour by scaling all three RGB channels down; at K = 100% the result is black regardless of the other values.

Is anything uploaded?

No. The conversion is pure arithmetic done in your browser; nothing is sent anywhere.

What is the CMYK to HEX Converter?

Convert CMYK (cyan, magenta, yellow, key) print colours to the equivalent HEX and RGB values for screen and web use. See a live swatch and copy the codes — everything runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

CMYK to HEX Converter

Name: CMYK to HEX Converter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Convert CMYK to HEX and RGB

CMYK is the four-ink model used for print (cyan, magenta, yellow and key black), while screens use RGB/HEX. This converter gives you the standard on-screen equivalent of a CMYK colour so you can preview a print colour on the web or pick a matching HEX value.

The conversion formula

C, M, Y, K as fractions 0–1
R = 255 × (1 − C) × (1 − K)
G = 255 × (1 − M) × (1 − K)
B = 255 × (1 − Y) × (1 − K)
HEX = #RRGGBB from those R, G, B values

This is the device-independent (“naive”) conversion — the same one browsers and CSS assume. It is exact as a definition but, like all CMYK→RGB maths, it is an approximation of how the colour will actually print.

Why print and screen differ

True press output depends on the ICC profile of the specific printer, the paper stock and the inks. Two printers fed the same CMYK values can produce visibly different results. Use this tool to get a faithful screen preview and a matching web colour, not a colour-managed proof.

Common uses

Previewing a brand’s CMYK print colour as a web HEX value.
Translating a printer’s CMYK spec into RGB for a website or app.
Sanity-checking that a CMYK mix lands near the colour you expect.

Everything is computed in your browser — nothing is uploaded.