Result
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Facts and limits of this method
| Intermediate step | CMYK is first converted to RGB, then to HEX |
|---|---|
| Input range | C, M, Y, K from 0% to 100% |
| Result format | #RRGGBB — six hexadecimal digits |
| Result case | Letters A–F are output uppercase |
When it misleads you
- This is a mathematical approximation, not the output of an actual printer's color profile — a real print may look different due to inks, paper and equipment.
- CMYK is a subtractive model for print, HEX/RGB is additive for screens; converting between them always loses some accuracy.
- The formula assumes the simplest ink-mixing scheme with no ICC profile — for color-critical print jobs use dedicated software.
- Rounding of percentages and byte values can shift the resulting shade slightly if you convert back and forth repeatedly.
How it is calculated
The C, M, Y and K percentages are converted to fractions from 0 to 1 by dividing by 100.
For each of R, G, B, the product (1 − color fraction) × (1 − black fraction) is computed, then multiplied by 255 and rounded to a whole number.
The resulting R, G, B numbers are converted to two-digit hexadecimal pairs.
The three pairs are joined in order with a leading "#" — producing a 6-digit HEX code.
Questions and answers
Why doesn't the on-screen color match what actually prints?
A screen shows light (RGB/HEX), while paper shows reflected light after ink is applied (CMYK); an exact match needs a profile for the specific printer and paper.
Can I use the result as a final design color?
Yes, as a guideline for interfaces and digital layouts — it's accurate enough for most everyday tasks.
Why does the code differ slightly after HEX→CMYK→HEX round-tripping?
Rounding of CMYK percentages and RGB byte values accumulates a small error at each step.
Is my data sent anywhere?
No, the whole calculation runs in your browser.