RGB to CMYK Converter
RGB in, CMYK out — with the working shown.
To convert RGB to CMYK, normalise the input, find the key plate, solve the other three plates, then check the gamut. For example, rgb(47 129 247) in RGB is cmyk(81% 47.8% 0% 3.1%) in CMYK.
This is a free RGB to CMYK converter. Type or paste any red, green and blue channel values into the field above and the CMYK value updates as you type, along with every other notation the web understands. CMYK is four subtractive ink percentages used for print.
Conversions run entirely in your browser using the same color engine as the rest of the site: values round-trip through linear sRGB and CIE XYZ rather than through an approximation, so what you copy is accurate to the last digit the format can carry.
How to convert RGB to CMYK
- Normalise the input. Read the RGB value and scale each component into the 0–1 range the maths expects.
- Find the key plate. K is 1 minus the largest of the three channels — the amount of black ink doing the heavy lifting.
- Solve the other three plates. Each of C, M and Y is (1 − channel − K) / (1 − K), then multiplied by 100 for a percentage.
- Check the gamut. Clamp anything that falls outside what an sRGB display can show, so the value you copy is the value you get.
Worked example: rgb(47 129 247) converts to cmyk(81% 47.8% 0% 3.1%). That color is Dodger Blue, and the tool above shows each intermediate step for whatever value you enter.
Common RGB to CMYK values
The twenty colors people look up most often, converted from RGB to CMYK. Every row is computed by the same engine as the tool above.
| Color | RGB | CMYK |
|---|---|---|
| White | rgb(255 255 255) | cmyk(0% 0% 0% 0%) |
| Black | rgb(0 0 0) | cmyk(0% 0% 0% 100%) |
| Red | rgb(255 0 0) | cmyk(0% 100% 100% 0%) |
| Lime | rgb(0 255 0) | cmyk(100% 0% 100% 0%) |
| Blue | rgb(0 0 255) | cmyk(100% 100% 0% 0%) |
| Yellow | rgb(255 255 0) | cmyk(0% 0% 100% 0%) |
| Cyan | rgb(0 255 255) | cmyk(100% 0% 0% 0%) |
| Magenta | rgb(255 0 255) | cmyk(0% 100% 0% 0%) |
| Silver | rgb(192 192 192) | cmyk(0% 0% 0% 24.7%) |
| Gray | rgb(128 128 128) | cmyk(0% 0% 0% 49.8%) |
| Maroon | rgb(128 0 0) | cmyk(0% 100% 100% 49.8%) |
| Olive | rgb(128 128 0) | cmyk(0% 0% 100% 49.8%) |
| Green | rgb(0 128 0) | cmyk(100% 0% 100% 49.8%) |
| Purple | rgb(128 0 128) | cmyk(0% 100% 0% 49.8%) |
| Teal | rgb(0 128 128) | cmyk(100% 0% 0% 49.8%) |
| Navy | rgb(0 0 128) | cmyk(100% 100% 0% 49.8%) |
| Orange | rgb(255 165 0) | cmyk(0% 35.3% 100% 0%) |
| Pink | rgb(255 192 203) | cmyk(0% 24.7% 20.4% 0%) |
| Gold | rgb(255 215 0) | cmyk(0% 15.7% 100% 0%) |
| Crimson | rgb(220 20 60) | cmyk(0% 90.9% 72.7% 13.7%) |
RGB and CMYK, briefly
RGB is three channels from 0 to 255 describing how hard the display drives its red, green and blue subpixels. Valid range: 0–255 per channel.
CMYK is four subtractive ink percentages used for print. Valid range: 0–100% per plate.
A note on CMYK: these values come from the standard naive formula with no ICC profile attached. They are indicative and useful for a mockup. For anything going on a press, get a printed proof on the actual stock — no formula substitutes for that.
Frequently asked questions
How do you convert RGB to CMYK?
1. Read the RGB value and scale each component into the 0–1 range the maths expects. 2. K is 1 minus the largest of the three channels — the amount of black ink doing the heavy lifting. 3. Each of C, M and Y is (1 − channel − K) / (1 − K), then multiplied by 100 for a percentage. 4. Clamp anything that falls outside what an sRGB display can show, so the value you copy is the value you get. The converter on this page does all of it as you type, and shows the working underneath.
What is rgb(255 0 0) in CMYK?
Pure red, rgb(255 0 0), is cmyk(0% 100% 100% 0%) in CMYK. There is a table of twenty common colors converted to CMYK further up this page.
What is rgb(47 129 247) in CMYK?
rgb(47 129 247) converts to cmyk(81% 47.8% 0% 3.1%). It is a dodger blue, and you can paste any other value into the field at the top of the page to convert it.
Is RGB to CMYK conversion lossless?
No. CMYK describes ink on paper and has no meaning without an ICC profile for a specific press, paper and ink set. The values here use the standard naive formula, which is fine for a mockup and should not be sent to a printer as-is — get a proof instead.
Can I use CMYK directly in CSS?
Not directly — CSS has no CMYK function. Convert to HEX, RGB or OKLCH for the stylesheet and keep the CMYK value for your print spec.
Does this RGB to CMYK converter support transparency?
Alpha is preserved wherever the target notation can carry it — eight-digit hex, rgb() / a, hsl() / a and the modern CSS spaces all round-trip an alpha channel. CMYK has no alpha, so it is dropped there.
Is my color data sent anywhere?
No. Every conversion on this site runs in your browser with no network request, no account and no analytics. You can disconnect and it keeps working.