RGB to CMYK Converter
Runs in your browser — your data is never uploaded.
Convert a screen colour to approximate CMYK ink percentages for print. This is the standard device-independent formula — the one every reference gives — and it is genuinely useful for getting close, filling in a spec sheet, or sanity-checking a design. What it is not is a colour-managed conversion: a real press result depends on the paper, the inks and an ICC profile that no browser tool has access to.
How to use RGB to CMYK
- 1
Enter the red, green and blue values, each 0–255.
- 2
Read the CMYK percentages.
- 3
For anything going to press, ask your printer for a profiled conversion.
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Frequently asked questions
Will these exact numbers print correctly?+
They will be close, not exact. Actual ink values depend on the press, the paper stock and an ICC profile describing both. Use this to understand and communicate a colour; use your printer’s profile for the final artwork.
Why do my bright screen colours look dull in print?+
Because screens emit light and ink absorbs it. Vivid RGB greens, oranges and blues sit outside what CMYK ink can reproduce, so they get mapped to the nearest printable colour. That gap is inherent, not a conversion fault.
What does the K channel do?+
K is black ink. Mixing C, M and Y to make black wastes ink and produces a muddy brown, so the black component is pulled out into its own channel — which is also why converting back can give different-looking numbers for the same colour.