RGB to CMYK Converter
Convert screen colors (RGB or HEX) to CMYK ink percentages for printing, or turn CMYK values back into RGB. Both sides update live as you type.
RGB / HEX screen
CMYK print
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Common print colors
How to convert RGB to CMYK
- Enter your color. Type a HEX code, drag the R, G and B sliders, or open the color picker.
- Read the CMYK values. Cyan, Magenta, Yellow and Black (K) percentages update instantly on the right.
- Going the other way? Edit the CMYK sliders or boxes and the RGB and HEX values update to match.
- Copy and use. Copy the CMYK, RGB or HEX value with one click and paste it into your design or print software.
RGB to CMYK formula
RGB values are first scaled to 0–1 by dividing by 255. Then:
- K = 1 − max(R′, G′, B′)
- C = (1 − R′ − K) ÷ (1 − K)
- M = (1 − G′ − K) ÷ (1 − K)
- Y = (1 − B′ − K) ÷ (1 − K)
To go back, R = 255 × (1 − C) × (1 − K), and the same for G with M and B with Y. This is the standard device-independent conversion used by most online converters and CSS. Professional print shops use ICC color profiles (such as FOGRA39 or GRACoL), so the final ink values your printer uses can differ slightly. For brand-critical work, ask your printer for their profile or a proof.
Why do colors look different in print?
Screens create color by adding light (RGB), while printers subtract light with ink on paper (CMYK). Very bright, saturated screen colors such as pure RGB green or electric blue cannot be reproduced exactly with four inks, so they print duller. Total ink coverage also matters: most printers prefer the sum of C+M+Y+K to stay under about 300%, which this tool shows for every color.
Frequently asked questions
What is the CMYK value of pure black?
Plain black is C 0, M 0, Y 0, K 100. For large black areas, printers often use a "rich black" such as C 60, M 40, Y 40, K 100 for a deeper result.
What is white in CMYK?
White is C 0, M 0, Y 0, K 0. In print, white is simply the paper with no ink.
Can I convert HEX to CMYK?
Yes. Paste any HEX code such as #FF5733 into the HEX box and the CMYK values appear instantly.
Is this converter accurate for professional printing?
It uses the standard mathematical conversion, which is great for design work and web-to-print estimates. Commercial printers convert with ICC profiles, which can shift values by a few percent.
Is the RGB to CMYK converter free?
Yes. It's free, needs no sign-up and runs entirely in your browser.