Enter a RGB color below to get the exact CMYK value instantly, plus every other format, right in your browser.
When you need RGB to CMYK
A color chosen on screen sometimes has to be described to a print shop, a sign maker or a PDF form that asks for cyan, magenta, yellow and black percentages. Starting from RGB, you convert to see roughly how much of each ink the color might need. This page uses the plain mathematical formula, so the output is a starting estimate for conversations, mockups and spreadsheets. For final production files, open the artwork in Photoshop or Illustrator and convert with the printer's ICC profile.
Typical uses
- Giving a print shop a rough ink breakdown for a logo color that exists only as RGB.
- Filling a CMYK field in a layout tool, then comparing it with the value obtained through a profile.
- Estimating whether a bright screen color may look duller on press before you order a proof.
How to convert RGB to CMYK
Normalize R, G and B to 0-1. The black key is K = 1 − max(R′, G′, B′). The remaining channels are C = (1 − R′ − K) / (1 − K), M = (1 − G′ − K) / (1 − K) and Y = (1 − B′ − K) / (1 − K).
The reverse conversion is R = 255 × (1 − C) × (1 − K), and likewise G from M and B from Y. Note that this is the standard formula conversion: real print output depends on the ICC profile of the press, inks and paper, so treat the result as a starting point, not a color-managed match.
Worked example
- Normalize the channels: R′ = 231 ÷ 255 = 0.906, G′ = 76 ÷ 255 = 0.298, B′ = 60 ÷ 255 = 0.235
- K = 1 − max(R′, G′, B′) = 1 − 0.906 = 0.094 → 9%
- C = (1 − R′ − K) ÷ (1 − K) = (1 − 0.906 − 0.094) ÷ 0.906 = 0 → 0%
- M = (1 − G′ − K) ÷ (1 − K) = (1 − 0.298 − 0.094) ÷ 0.906 = 0.671 → 67%
- Y = (1 − B′ − K) ÷ (1 − K) = (1 − 0.235 − 0.094) ÷ 0.906 = 0.74 → 74%
rgb(231, 76, 60) = cmyk(0%, 67%, 74%, 9%)
Tip: Before approving brand-critical colors, ask the printer for a hard or soft proof. Send them the RGB, this CMYK estimate and the paper stock name, so they can tell you whether the color is reproducible on their press.
Common colors: RGB to CMYK
| Color | RGB | CMYK |
|---|---|---|
| Red | rgb(255, 0, 0) | cmyk(0%, 100%, 100%, 0%) |
| Orange | rgb(255, 165, 0) | cmyk(0%, 35%, 100%, 0%) |
| Yellow | rgb(255, 255, 0) | cmyk(0%, 0%, 100%, 0%) |
| Lime | rgb(0, 255, 0) | cmyk(100%, 0%, 100%, 0%) |
| Green | rgb(0, 128, 0) | cmyk(100%, 0%, 100%, 50%) |
| Cyan | rgb(0, 255, 255) | cmyk(100%, 0%, 0%, 0%) |
| Teal | rgb(0, 128, 128) | cmyk(100%, 0%, 0%, 50%) |
| Blue | rgb(0, 0, 255) | cmyk(100%, 100%, 0%, 0%) |
| Navy | rgb(0, 0, 128) | cmyk(100%, 100%, 0%, 50%) |
| Purple | rgb(128, 0, 128) | cmyk(0%, 100%, 0%, 50%) |
| Magenta | rgb(255, 0, 255) | cmyk(0%, 100%, 0%, 0%) |
| Pink | rgb(255, 192, 203) | cmyk(0%, 25%, 20%, 0%) |
| Brown | rgb(165, 42, 42) | cmyk(0%, 75%, 75%, 35%) |
| Gray | rgb(128, 128, 128) | cmyk(0%, 0%, 0%, 50%) |
| Black | rgb(0, 0, 0) | cmyk(0%, 0%, 0%, 100%) |
| White | rgb(255, 255, 255) | cmyk(0%, 0%, 0%, 0%) |
Frequently asked questions
Can I paste these numbers straight into a print-ready file?
Treat them as a draft. Production files should be converted with the ICC profile your printer specifies, for example one for coated or uncoated paper, and the profile can give noticeably different percentages than this formula. Ask which profile the printer uses before finalizing.
How should I send a whole palette to the printer?
Convert each color separately and record the results in a table beside the HEX codes and color names so the printer can cross-check. Mark which colors are critical to the brand, because those deserve a physical proof, while the rest can rely on the estimate.
Why does the printed color look different from my screen?
Screens mix light (additive RGB) while print mixes inks (subtractive CMYK), and the printable gamut is narrower. The exact result depends on the ICC profile, inks and paper; this converter uses the standard formula without color management, so treat it as an approximation.
What is the K channel?
K is the key (black) plate. Printing black with a dedicated ink instead of mixing 100% cyan, magenta and yellow gives deeper blacks, sharper text and saves ink.
Can I use CMYK in CSS?
No, the web works in RGB. Convert CMYK values to HEX or RGB before using them on a website; that is exactly what this tool does.
More color converters
Need to grab a color from an image or screenshot? Try the free Pixel Color Picker →