HEX to CMYK Converter

How to use the HEX to CMYK Converter

Type or paste a hex color such as #6366F1 into the HEX field, or choose one with Pick colour.

The CMYK field updates as you type and shows cmyk(c%, m%, y%, k%).

Use the percentages as a starting point in your print layout and confirm them with your printer.

Convert HEX to CMYK for print

A HEX to CMYK converter turns a web color code into cyan, magenta, yellow and black ink percentages. It gives you a quick starting point when a logo or brand color defined for screens has to appear in a print layout, on a sign or in a packaging brief.

Light versus ink

Hex codes describe light: red, green and blue added together on a screen, with all three at full strength making white. CMYK describes ink on paper, which works the other way round. Each ink absorbs part of the light, so more ink gives a darker result. Cyan is the opposite of red, magenta of green and yellow of blue, while K (key) is black ink that deepens shadows and saves colored ink.

The formula this tool uses

The hex code is decoded to RGB and each channel is divided by 255. Then:

K = 1 − max(R, G, B)
C = (1 − R − K) / (1 − K)
M = (1 − G − K) / (1 − K)
Y = (1 − B − K) / (1 − K)
(when K = 1 the result is 0%, 0%, 0%, 100%)

Worked example with the indigo #6366F1:

#6366F1 → rgb(99, 102, 241)
R = 0.3882   G = 0.4000   B = 0.9451
K = 1 − 0.9451                       = 0.0549 → 5.5%
C = (1 − 0.3882 − 0.0549) / 0.9451   = 0.5892 → 58.9%
M = (1 − 0.4000 − 0.0549) / 0.9451   = 0.5768 → 57.7%
Y = (1 − 0.9451 − 0.0549) / 0.9451   = 0      → 0%
→ cmyk(58.9%, 57.7%, 0%, 5.5%)

Pure black #000000 becomes cmyk(0%, 0%, 0%, 100%), and white #FFFFFF becomes all zeros: no ink at all, so the paper shows through.

This is not a color-managed conversion

The formula above is the textbook mathematical conversion. Professional print work uses ICC color profiles that describe a specific press, ink set and paper, and those produce different numbers, often with less black and more colored ink in the shadows. The formula also can't warn you that a color is outside the printable range: vivid screen colors such as #1E90FF will print noticeably duller than they look.

Treat the result as an informed first guess. For anything that must match, ask your printer for their profile, convert in a color-managed application and approve a physical proof. Brand colors that must be exact are often specified as spot inks rather than CMYK mixes.

Other details

Percentages are rounded to one decimal place.
The alpha byte of an eight-digit hex code is ignored, since ink has no transparency setting. Flatten semi-transparent colors onto white first, as described in RGBA to CMYK.
Because K takes the entire grey component, at least one of C, M or Y is always 0% in the output.

To go the other direction, use CMYK to HEX, or start from channel values with RGB to CMYK.

Frequently asked questions

Are these CMYK values ready to send to a printer?

Treat them as a starting point. Print shops convert with ICC profiles for their press and paper, which can give quite different percentages. Ask for their profile or a proof when color accuracy matters.

Why does my printed color look duller than on screen?

Screens can show brighter, more saturated colors than process inks can reproduce. Vivid blues, greens and oranges are common examples, and they print closer to the nearest achievable color.

What does the K in CMYK stand for?

K stands for key, the black ink plate. Black is printed separately because mixing full cyan, magenta and yellow gives a muddy dark brown rather than a clean black.

Why is one of C, M or Y always 0%?

The formula puts the whole grey component of the color into black (K). What remains is at most two colored inks, so the ink matching the strongest RGB channel is always zero.