Converter
CMYK to RGB Converter
For getting a print colour onto a screen as RGB channel values. Drag the four ink sliders and watch the channels update.
These values are mathematical approximations. Ink, paper, press calibration and colour profile all change the printed result — always approve colour from a physical proof. Full disclaimer.
How the conversion works #
Read it as two filters stacked on white light. The chromatic ink removes some of one channel; the black ink then removes a proportion of everything that is left. Because the two multiply rather than add, black ink at 50% halves whatever the other inks let through, which is exactly how a real tint behaves on paper.
A worked example #
Process red, C 0, M 100, Y 100, K 0.
- R = 255 × (1 − 0) × (1 − 0) = 255. Cyan is the only ink that removes red, and there is none.
- G = 255 × (1 − 1) × 1 = 0. Magenta at full strength removes all green.
- B = 255 × (1 − 1) × 1 = 0. Yellow at full strength removes all blue.
- The result is 255, 0, 0, or
#FF0000.
Which reveals something the arithmetic hides: it claims that magenta and yellow ink together produce pure screen red. On paper they do not. They produce a warm red that is visibly less intense, because real inks are not the perfect filters the formula pretends they are. This is the single biggest gap between the simple model and reality.
Common CMYK to RGB values #
| Colour | CMYK | RGB | HEX |
|---|---|---|---|
| Black | 0, 0, 0, 100 | 0, 0, 0 | #000000 |
| White | 0, 0, 0, 0 | 255, 255, 255 | #FFFFFF |
| Red | 0, 100, 100, 0 | 255, 0, 0 | #FF0000 |
| Lime | 100, 0, 100, 0 | 0, 255, 0 | #00FF00 |
| Blue | 100, 100, 0, 0 | 0, 0, 255 | #0000FF |
| Yellow | 0, 0, 100, 0 | 255, 255, 0 | #FFFF00 |
| Cyan | 100, 0, 0, 0 | 0, 255, 255 | #00FFFF |
| Magenta | 0, 100, 0, 0 | 255, 0, 255 | #FF00FF |
| Dodger blue | 88, 44, 0, 0 | 30, 144, 255 | #1E90FF |
| Navy | 100, 100, 0, 50 | 0, 0, 128 | #000080 |
| Teal | 100, 0, 0, 50 | 0, 128, 128 | #008080 |
| Forest green | 76, 0, 76, 45 | 34, 139, 34 | #228B22 |
| Olive | 0, 0, 100, 50 | 128, 128, 0 | #808000 |
| Orange | 0, 35, 100, 0 | 255, 165, 0 | #FFA500 |
| Crimson | 0, 91, 73, 14 | 220, 20, 60 | #DC143C |
| Maroon | 0, 100, 100, 50 | 128, 0, 0 | #800000 |
| Purple | 0, 100, 0, 50 | 128, 0, 128 | #800080 |
| Hot pink | 0, 59, 29, 0 | 255, 105, 180 | #FF69B4 |
| Silver | 0, 0, 0, 25 | 192, 192, 192 | #C0C0C0 |
| Charcoal | 32, 13, 0, 69 | 54, 69, 79 | #36454F |
Questions #
Is CMYK to RGB lossy?
The arithmetic is not, but the round trip is. Every CMYK combination maps to some RGB colour, so nothing is lost going this direction. Going back the other way is where colours get clipped, because RGB can describe colours that no ink combination can reach.
Why does my print file look washed out when I open it on screen?
Usually because the RGB it converts to is a fair representation of the ink, and ink is less vivid than a backlit display. The file is not damaged. If you need the screen version to have more life in it, treat it as a separate design decision rather than a conversion problem.
Can I use this to repurpose print artwork for a website?
For flat colours, yes. For photographs, no — open the original RGB photograph instead. A photo that has already been converted to CMYK has had its out-of-gamut colours discarded, and converting it back does not bring them back.
What RGB space does the result assume?
Treat the output as sRGB, which is the default for the web and for untagged files. If you need Adobe RGB or Display P3 values, convert with colour-managed software rather than plain arithmetic.