HEX to CMYK Converter
Type a HEX code and get its CMYK percentages for print, plus the RGB values behind it.
How to use
- Step 1Paste the HEX code (the # is optional, and abc is read as #aabbcc) or pick the color with the picker. The four percentages, the RGB values and the swatch update at once.
- Step 2Copy the CMYK line in Illustrator's notation, C=88 M=44 Y=0 K=0, and type the numbers into the color dialog of Illustrator, InDesign, Affinity or Canva, or into the printer's order form.
- Step 3For anything larger than a business card, convert the same HEX once more with the printer's ICC profile in Photoshop, or ask for a proof: the formula here is profile-free and gives more black and less colored ink than a press profile would.
What the six digits hold and what the four percentages are for
A HEX code is #RRGGBB: two hexadecimal digits for each of red, green and blue, 00 to ff, which is 0 to 255 in decimal. #1e90ff is red 30, green 144, blue 255. The three-digit shorthand doubles each digit, so #f80 is #ff8800. The numbers describe sRGB light, the standard of web pages, phones and most monitors.
CMYK percentages are the amounts of cyan, magenta, yellow and black ink a press or a print dialog lays down. Designers meet them when a screen color has to go on paper: a logo drawn in Figma, a brand HEX from a website that the print shop asks for in CMYK, or a color picked on screen for a flyer laid out in Canva or InDesign.
The formula, step by step
First the channels are scaled to 0–1: R′ = R ÷ 255, G′ = G ÷ 255, B′ = B ÷ 255. Black takes the darkness all three share: K = 1 − max(R′, G′, B′). The colored inks get what remains after black: C = (1 − R′ − K) ÷ (1 − K), M = (1 − G′ − K) ÷ (1 − K), Y = (1 − B′ − K) ÷ (1 − K). Pure black has K = 1 and the division would be 0 ÷ 0, so C, M and Y are set to 0. The results are multiplied by 100 and rounded to whole percents.
Example: #1e90ff. R′ = 0.118, G′ = 0.565, B′ = 1.000, so K = 0; C = 1 − 0.118 = 0.882 → 88; M = 1 − 0.565 = 0.435 → 44; Y = 0. The result is C=88 M=44 Y=0 K=0. A mid grey #808080 gives 0/0/0/50: the formula always moves everything the three channels share into black, which is the most economical separation but not the one a press profile chooses.
The pure colors in each space, with this formula:
| Color | HEX | RGB | CMYK (formula) |
|---|---|---|---|
| Red | #ff0000 | 255, 0, 0 | 0 / 100 / 100 / 0 |
| Green | #00ff00 | 0, 255, 0 | 100 / 0 / 100 / 0 |
| Blue | #0000ff | 0, 0, 255 | 100 / 100 / 0 / 0 |
| Black | #000000 | 0, 0, 0 | 0 / 0 / 0 / 100 |
| White | #ffffff | 255, 255, 255 | 0 / 0 / 0 / 0 |
| Mid grey | #808080 | 128, 128, 128 | 0 / 0 / 0 / 50 |
What the numbers leave out
Gamut. Saturated screen colors have no ink equivalent: a press cannot print #00ff00 or #0000ff, so a profile conversion in Photoshop picks the nearest printable color, and its CMYK looks nothing like the formula's tidy 100/0/100/0. Pure blue, for instance, comes out of Photoshop's SWOP profile near 88/77/0/0, and black #000000 as 75/68/67/90. The formula does not know any of this and returns clean numbers for colors that cannot be printed.
Ink limit. Presses cap the total of the four percentages (about 300 for SWOP, 330 for FOGRA39 coated stock, less for newsprint). The formula never exceeds 300 because it puts the shared part into K, but a profile can return 75/68/67/90, which is 300 percent for black alone, and the printer may ask you to bring it down.
Black. The formula converts #000000 to plain 100 K. On a press, 100 K alone is a slightly weak, warm black; large areas are usually printed as a rich black such as 60/40/40/100, while small text stays 100 K to avoid misregistration. Ask the printer which they want; the formula cannot decide it.
Paper and profile. The same CMYK numbers print differently on coated and uncoated stock and on different presses. A brand guide that lists CMYK next to HEX has already settled the question for one paper; use its numbers rather than converting the HEX again.
When the formula is the right tool
- Filling in a form or a spec sheet that asks for CMYK with no profile named.
- Comparing values with other web calculators, spreadsheets and CSS tools, which all use the same formula.
- Getting a quick idea of how much of each ink a color needs, or seeing that a screen color is mostly black.
- Not the right tool: the final separation of a print job, matching a brand color on packaging, or anything for which the printer supplied an ICC profile. Convert there, with the profile.
Questions and answers
Why does Illustrator give different CMYK values?
Illustrator converts through the document's CMYK working space: U.S. Web Coated (SWOP) v2 in the North American defaults, Coated FOGRA39 in the European ones. The profile models real inks and paper and prefers separations with less black, so #000000 becomes 75/68/67/90 and #0000ff about 88/77/0/0. This page uses the profile-free formula that web calculators share. Both are legitimate; the profile answer is the one that predicts the press.
What is rich black?
A black printed with cyan, magenta and yellow under the 100 percent black, typically 60/40/40/100 (240 percent coverage) or the cooler 30/30/30/100. It looks deeper than black ink alone on large areas. It is not used for body text or thin lines, where four plates would need perfect registration, and 100/100/100/100 (registration black) is reserved for printer's marks because it exceeds every ink limit. This page never produces a rich black: #000000 gives 0/0/0/100, so add the extra inks by hand where the printer wants them.
Should I send the printer the HEX or the CMYK?
The CMYK, or a PANTONE® number for a spot color. A HEX would be converted by the printer's own profile with results you never saw; converting it yourself, checking the swatch and sending CMYK keeps the decision in your hands. Send the HEX too if the color must also match on screen, and expect the two to differ.
Why is black 100 and the other inks 0 for every grey?
The formula assigns everything that red, green and blue share to K and leaves only the excess for the colored inks, so a neutral grey has no excess and becomes a black tint: #808080 is 0/0/0/50. A press profile often prints greys with all four inks, which hides the coarser black dots and lets the grey be tuned warm or cool. Both print as grey; the four-ink version is smoother on coated paper, the K-only version cannot drift in hue if the press runs slightly off.