RGB to CMYK Converter

How to use the rgb to cmyk converter

1. Enter or pick your colour.
2. Read every notation below, updated as you type.
3. Copy whichever one you need.

About this tool

RGB is additive — light adding up to white. CMYK is subtractive — ink absorbing light, so more ink means darker. They are not just different notations for one colour space, and that is why the conversion is genuinely approximate rather than merely rounded.

The CMYK figures are a direct arithmetic conversion with no colour profile attached. That is what every browser-based converter does, and it is a reasonable starting point — but it cannot tell you what will come off a press, because that depends on the ink, paper and profile. Vivid screen colours in particular have no CMYK equivalent at all and will print duller than they look here.

The K channel exists because mixing cyan, magenta and yellow gives a muddy brown rather than black, and because printing three inks where one will do wastes ink and soaks the paper.

Common uses

• A rough CMYK starting point for a print job.
• Checking whether a screen colour is likely to print badly.
• Filling in a CMYK field in a design tool.

Frequently asked questions

Will these values print exactly?

No. A true conversion needs an ICC profile for the specific press, ink and paper. Treat these as a starting point and proof with your printer.

Why do bright colours look duller in print?

Many vivid screen colours are outside what CMYK ink can reproduce at all. The conversion picks the nearest printable colour, which is duller.

What is the K in CMYK?

Black — 'key'. Mixing the other three gives a muddy brown rather than true black, and using one ink instead of three saves ink and paper.