Why convert hex to CMYK?

Screens use additive RGB, but printing uses subtractive CMYK ink. Converting gives you the cyan, magenta, yellow and key (black) ink percentages needed for print artwork.

Is the CMYK conversion exact for print?

It uses the standard mathematical RGB-to-CMYK formula, which is a close approximation. True print colour also depends on the printer profile, ink and paper, so treat it as a starting point and check a proof.

What does the K in CMYK stand for?

K is the "key" plate — black. It is used instead of B to avoid confusion with blue, and dates from printing where the black plate was the key alignment layer. Black ink also gives deeper shadows and saves coloured ink.

Does it accept 3-digit hex codes?

Yes. Shorthand like #abc is expanded to #aabbcc before conversion, and the leading hash is optional.

Why is my CMYK black not 0,0,0,100?

Pure hex black (#000000) does give 0,0,0,100. But a dark colour with a slight tint converts to a mix of inks plus a high K value, because the formula extracts the most black possible first, then the remaining colour.

Does this upload my colours?

No. The conversion happens entirely in your browser — nothing is uploaded or stored.

Hex to CMYK Converter

Hex to CMYK converter

Paste a hex colour code and get the matching CMYK ink percentages — cyan, magenta, yellow and key (black) — for print and design work, with a live swatch and a one-click copy. Screens mix light (RGB), but printers mix ink (CMYK), so a hex value from your design has to be translated before it goes to press.

How it works

The tool first parses the hex into red, green and blue (0–255), expanding 3-digit shorthand if needed. It normalises each channel to a 0–1 range, then applies the standard RGB-to-CMYK formula:

K (black) = 1 − max(R, G, B)
C = (1 − R − K) / (1 − K)
M = (1 − G − K) / (1 − K)
Y = (1 − B − K) / (1 − K)

Each result is multiplied by 100 and rounded to a whole percent. Pure black is a special case (K = 100, the rest 0).

Example

For #3b82f6 (a blue), the RGB is 59, 130, 246. Then:

K = 1 − 246/255 = 0.035 → 4%
C = (1 − 59/255 − 0.035) / (1 − 0.035) = 76%
M = (1 − 130/255 − 0.035) / 0.965 = 47%
Y = (1 − 246/255 − 0.035) / 0.965 = 0%

Result: cmyk(76%, 47%, 0%, 4%).

It is a close mathematical approximation; final print colour also depends on your printer profile. Everything runs in your browser — nothing is uploaded.