CMYK Color Converter
Convert any hex or RGB color to CMYK for print.
This tool runs entirely in your browser. Your files are never uploaded to a server.
76%
Cyan
47%
Magenta
0%
Yellow
4%
Key (black)
cmyk(76%, 47%, 0%, 4%)
CMYK values are approximate — for exact print output, use your print shop's color profile (ICC).
What this tool does
Converts a hex or RGB color into CMYK (Cyan, Magenta, Yellow, Key/black) percentages — the subtractive color model used for professional printing.
How to use it
Pick a color with the color swatch or type a hex code directly. The four CMYK percentages and a ready-to-copy cmyk() string update immediately; click the copy icon to copy the string.
Worked example
The default color #3b82f6 (RGB 59, 130, 246) converts to cmyk(76%, 47%, 0%, 4%) — 76% cyan, 47% magenta, 0% yellow, and 4% black (key).
Formula
K (black) = 1 − max(R', G', B'), where R', G', B' are the RGB channels scaled to 0–1. C = (1 − R' − K) ÷ (1 − K), M = (1 − G' − K) ÷ (1 − K), Y = (1 − B' − K) ÷ (1 − K). Each result is then expressed as a percentage. Pure black (0, 0, 0) is a special case returning 0% C/M/Y and 100% K.
Why the result is only an approximation
This is a naive device-independent formula, not a color-managed conversion — real print production uses ICC color profiles specific to the printer, ink set, and paper, which account for how inks actually mix and how a particular press reproduces color. The same hex value converted this way and converted through a professional print workflow can come out noticeably different, especially for saturated colors near the edge of the CMYK gamut.
Limitations
RGB and CMYK cover different ranges of visible color, called gamuts — RGB, an additive model based on light, can represent some bright, saturated colors that CMYK's subtractive ink-mixing model cannot reproduce exactly, so very vivid on-screen colors may print duller than expected. This tool doesn't apply any specific ICC profile, rich-black adjustment, or total-ink-coverage limit that a print shop's software would use.
Scope, sources and privacy
The RGB-to-CMYK formula used here is the standard simplified conversion taught in color theory and used as a starting estimate before professional color management. The conversion runs entirely in your browser; the color you enter is never uploaded.
Frequently Asked Questions
- What is CMYK used for?
- CMYK is the standard color model for print — printers mix cyan, magenta, yellow and black ink to reproduce colors, unlike screens which use RGB light.
- Why might printed colors look different from my screen?
- RGB (screen) and CMYK (print) have different color gamuts — this conversion is a mathematical approximation, and actual printed results also depend on paper, ink and printer calibration.
- Should I design in RGB or CMYK?
- Design digital work in RGB/hex; convert to CMYK only when preparing final files for professional printing, ideally using your print shop's color profile.