CMYK to HEX Converter — Free CMYK to Hex Colour Tool for Print-to-Web Work

Brand guidelines, print proofs and packaging specs speak CMYK — four ink percentages. Screens speak hex. This CMYK to HEX converter is the translator between the print shop and the browser: type the cyan, magenta, yellow and black (key) percentages from your print specification and get the hex code and RGB values for the closest screen colour, with a live preview swatch. The maths is the standard naive conversion used everywhere the two worlds meet — each RGB channel is 255 × (1 − ink) × (1 − black) — done instantly in your browser. The preloaded values, 87 / 0 / 7 / 54, are the CMYK build of this site’s deep teal and convert to #0f766e, so you can verify the tool against a colour you can also look up in the other direction. Bear the honest caveat in mind, spelled out below: CMYK and RGB are different colour worlds, and this gives the standard mathematical match, not a colour-managed proof.

How the CMYK to hex conversion works

CMYK is subtractive: inks absorb light from white paper, so more ink means a darker colour, and the K channel adds black directly. The standard conversion first recovers RGB: R = 255 × (1 − C) × (1 − K), and likewise for green with M and blue with Y. For the preloaded teal — C 87, M 0, Y 7, K 54 — that gives R = 255 × 0.13 × 0.46 ≈ 15, G = 255 × 1 × 0.46 ≈ 118 (rounded from 117.3 by the formula’s standard rounding in this tool), B = 255 × 0.93 × 0.46 ≈ 110, which writes as hex #0f766e. The K channel is doing heavy lifting in that example: it darkens all three channels at once, which is why rich print colours with high black values often look deeper than their hex twins. Pure print red (0, 100, 100, 0) gives #ff0000, and full black (0, 0, 0, 100) gives #000000 — the two calibration points worth testing any converter with.

The caveat that actually matters: gamut

CMYK’s colour gamut — the set of colours it can produce — is smaller than a screen’s and shaped differently. Vivid screen colours like electric blues and neon greens simply cannot be printed with four inks, and some printed colours (deep rich blacks built from all four inks, metallic-adjacent tones) have no single hex equivalent. This converter applies the standard formula faithfully, which is the right answer for the everyday job: carrying a brand colour from a print guideline into a website, a slide deck or an app. It is not a substitute for colour-managed proofing when a printed result must match a screen colour contractually — that job belongs to ICC profiles and press proofs, and any tool promising it from four percentages alone is overselling. Use this for faithful translation; use a proof for guarantees.

Practical tips for print-to-web work

Take the CMYK values from the brand document, not from a screenshot of the printed piece — lighting and paper stock shift what a camera sees. If the guideline lists both a CMYK build and a Pantone reference, convert the CMYK for web use and keep the Pantone for printers; the hex you derive here is the web member of the family. Expect the screen version to look slightly brighter and cleaner than the printed one: screens emit light, paper reflects it, and the same formula cannot change physics. Finally, when a CMYK build has K at 100 with other inks at 0, the result is pure black #000000; builds with all four inks high (“rich black”) convert to very dark near-blacks whose exact hex depends on the full set of values, so convert the actual build rather than assuming black.

Frequently asked questions

What hex is CMYK 87, 0, 7, 54?

#0f766e, rgb(15, 118, 110) — the converter is preloaded with these values so you can see the full worked example.

Why does the printed colour look different from the hex on screen?

Because they are made differently: ink on paper reflects light, screens emit it, and the CMYK gamut cannot reproduce every screen colour. The formula gives the standard match, not an identical appearance.

What does the K in CMYK stand for?

Key — the black plate. It is called key (rather than B, which would clash with blue) after the key plate that other colours were aligned to in traditional printing.

Can this convert rich black?

Yes — enter the full four-ink build (for example 60, 40, 40, 100) and you get the corresponding very dark hex. The result depends on all four values, which is exactly why rich black is a build, not a single number.

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CMYK to HEX Converter — Convert Print Colours to Web Hex Codes