RGB to CMYK Converter
Convert RGB color values to CMYK using real ICC profiles or a simple formula. Enter red, green, and blue values and see a live soft proof of how your color will look in print.
RGB Input
CMYK Output
#ff00ff
Frequently asked questions
How does this tool convert RGB to CMYK?
This tool offers two conversion modes. Formula mode uses a direct mathematical conversion from RGB channel values to CMYK percentages — fast, but it doesn't account for real-world printing conditions. ICC Profile mode uses industry-standard ICC color profiles and the LittleCMS color engine (running in your browser via WebAssembly) to perform the same kind of color transform that professional pre-press software uses.
What is an ICC profile and why does it matter?
An ICC profile is a standardized file that describes how a specific device (like a printer on a specific paper stock) reproduces color. Without a profile, a color conversion is just math — it doesn't account for how ink actually behaves on paper. With a profile, the conversion maps your color through a real color model, giving you CMYK values that will actually produce the color you expect on press.
Which ICC profile should I choose?
That depends on where your work will be printed. For North American commercial printing on coated paper, GRACoL 2013 is the current standard. For European printing, FOGRA59 (eciCMYK v2) or FOGRA51 (PSO Coated v3) are common choices. For Japanese printing, Japan Color 2011 Coated is standard. If you're unsure, ask your print provider which profile they recommend — or use Generic CMYK as a reasonable starting point.
What's the difference between GRACoL, SWOP, and FOGRA profiles?
These are standards defined by different regional organizations. GRACoL (Idealliance) targets sheetfed commercial printing in North America. SWOP (also Idealliance) targets web offset printing (magazines, catalogs). FOGRA (ECI) covers European printing standards. Japan Color covers Japanese printing. Each defines specific ink, paper, and press conditions, so the same RGB color can produce different CMYK values depending on the profile.
What's wrong with formula-based conversion?
Formula mode uses a simple algebraic inversion (R,G,B → C,M,Y,K) that treats all inks and papers as identical. In reality, different paper stocks absorb ink differently, and different ink sets have different gamuts. A formula conversion of a vivid blue might give you C:100 M:100 Y:0 K:0, while a proper ICC conversion for coated paper might give C:95 M:78 Y:0 K:0 — a significant difference in ink usage and appearance.
What does the soft proof show me?
When using ICC Profile mode, the output swatch shows a soft proof — a simulation of how your color will actually look when printed and viewed back on screen. The tool converts your color to CMYK through the selected profile, then converts those CMYK values back to RGB. Any difference between your input color and the soft proof represents color that will be lost in printing due to the CMYK gamut being smaller than RGB.
Does this conversion happen on your servers?
No. The entire conversion runs in your browser using WebAssembly. The ICC profile is downloaded once and cached, and the LittleCMS color engine runs locally. No color data is ever sent to a server, and conversions are instantaneous.
Why do some colors look very different in the soft proof?
Highly saturated colors — especially bright greens, electric blues, and neon colors — often fall outside the CMYK gamut. The soft proof shows you this gap honestly. If your input color and the soft proof look noticeably different, that color simply cannot be reproduced accurately with CMYK inks on that paper type. You may want to adjust your design colors to ones that translate better.
Can I use this for Pantone or spot color matching?
This tool converts to process CMYK (four-color printing). It does not handle Pantone or other spot color systems, which use pre-mixed inks. If you need exact brand color matching, consult the Pantone Bridge guides which show the closest process CMYK equivalent for each Pantone color.
What rendering intent is used for the conversion?
The tool uses Relative Colorimetric rendering intent with Black Point Compensation. This is the most common intent for color conversion in graphic arts — it preserves colors that are within the destination gamut and clips out-of-gamut colors to the nearest reproducible equivalent, while mapping the black points of both profiles to maintain shadow detail.