Convert RGB to CMYK
Convert CSS rgb(...) colors like rgb(255, 87, 51) into CMYK values like cmyk(0%, 66%, 80%, 0%)—fast, private, and right in your browser.
- Paste a single RGB color or a whole palette
- Use one color per line for batch conversion
- Copy your CMYK results instantly
Quick start
- Paste your RGB color(s) into the input.
- Use one color per line.
- Copy the CMYK results.
Single color
Input:
rgb(255, 87, 51)Output:
cmyk(0%, 66%, 80%, 0%)Palette / batch conversion
Input:
rgb(255, 0, 255)
rgb(0, 255, 255)
rgb(38, 38, 38)Output (example):
cmyk(0%, 100%, 0%, 0%)
cmyk(100%, 0%, 0%, 0%)
cmyk(0%, 0%, 0%, 85%)CMYK conversions are typically approximations. Small differences are normal depending on how CMYK is interpreted.
What RGB means
RGB stands for Red, Green, Blue—the three light channels used by screens.
- Each channel is an integer from 0 to 255.
rgb(0, 0, 0)is black.rgb(255, 255, 255)is white.
RGB is the default “screen-native” format, which is why you see it in:
- CSS and browser APIs
- design tools that export colors as
rgb(…) - canvas / image processing code
What CMYK means (Cyan, Magenta, Yellow, Key/Black)
CMYK is a subtractive color model used for printing.
- C = Cyan
- M = Magenta
- Y = Yellow
- K = Key (Black)
Why “subtractive”?
- Paper reflects light.
- Inks absorb (subtract) parts of that light.
- More ink usually means a darker result.
In real print workflows, CMYK values depend on:
- the ink set
- the paper stock
- press calibration
- an ICC profile (the rules that map colors)
Why RGB → CMYK is an approximation
RGB values represent how a color looks on an sRGB screen.
CMYK values represent how inks might reproduce a color on paper.
There isn’t a single universal mapping between the two. Accurate conversion requires a specific CMYK profile (and often proofing). Without that, conversion tools must make assumptions.
This is still very useful when you need:
- a quick print estimate from web colors
- rough CMYK values for brand documents
- a sanity check before proper color-managed export
For print-critical work, use a color-managed workflow with the correct ICC profile in your design tool.
How RGB → CMYK conversion works
Conceptually, the converter does this for each line:
- Read RGB channels (0–255)
- Convert into CMYK percentages using a standard (profile-free) method
- Format the result as
cmyk(c%, m%, y%, k%)
Because step (2) depends on assumptions, rounding and minor differences are expected.
Common mistakes (and quick fixes)
Extra spaces at the start/end of a line
Leading and trailing spaces are ignored.
✅ rgb(255, 87, 51)
🚫 rgb(255, 87, 51)
Missing “rgb( … )” wrapper
Each line must be a full CSS-style RGB string:
✅ rgb(17, 24, 39)
🚫 17, 24, 39
Values outside 0–255
RGB channels should stay in range:
✅ rgb(0, 128, 255)
🚫 rgb(300, -5, 260)
Practical uses
- Create print handoff values from web brand colors
- Build guidelines that show both RGB (web) and CMYK (print)
- Normalize palettes across teams (screen-first to print-first)
- Get a quick estimate before doing a proper ICC-profile conversion
If you’re taking a website palette into print, RGB → CMYK gives you a fast baseline—then you can refine it with the right profile and proofs in your print workflow.
