RGB to CMYK converter
Paste a HEX code or RGB values, get CMYK percentages for print, and see an approximate preview of how the colour prints. No sign-up, works on your phone.
CMYK for print
100 · 100 · 0 · 0
C · M · Y · K in %
RGB / HEX for screen
0 · 0 · 255
#0000FF
Screen vs print preview
The print preview is a simulation of the typical CMYK shift, not a measurement of a specific machine. Matte material softens colour further; gloss keeps it punchier.
How the conversion works
Screens mix red, green and blue light; printers lay down cyan, magenta, yellow and black ink. The two systems are opposites, so converting between them is arithmetic:
- RGB → CMYK: K = 1 − max(R, G, B) ÷ 255. Then C = (1 − R ÷ 255 − K) ÷ (1 − K), M uses G, Y uses B. Multiply by 100 for percentages.
- CMYK → RGB: R = 255 × (1 − C) × (1 − K), G uses M, B uses Y.
That formula is what every free converter online uses, and it is honest about one thing only: the ink percentages. It says nothing about how the colour will look, because ink on vinyl cannot reproduce every colour a backlit screen can. That is why the preview above dulls saturated colours — pure blue (#0000FF) prints closer to a navy-violet, lime green goes leafy, neon orange goes brick. If you want to understand why, read RGB vs CMYK for printing.
Common colours and their print values
| Colour | HEX (screen) | Formula CMYK | What actually prints well |
|---|---|---|---|
| Pure red | #FF0000 | 0 · 100 · 100 · 0 | 0 · 100 · 100 · 0 — prints fine, slightly warmer |
| Pure blue | #0000FF | 100 · 100 · 0 · 0 | Use 100 · 70 · 0 · 0 — the formula value prints purple |
| Lime green | #00FF00 | 100 · 0 · 100 · 0 | Prints as a leaf green; neon lime is out of gamut |
| Orange | #FF6600 | 0 · 60 · 100 · 0 | 0 · 50 · 100 · 0 for a clean bright orange |
| Magenta | #FF00FF | 0 · 100 · 0 · 0 | Prints as pink-magenta; the screen version glows more |
| Black text | #000000 | 0 · 0 · 0 · 100 | Keep 0 · 0 · 0 · 100 for text; 60 · 40 · 40 · 100 for big black panels |
More print-safe starting points, organised by colour family, are in our CMYK colour chart — including the printable PDF.
FAQ
How do I convert RGB to CMYK?
Enter a HEX code or RGB values above. The converter applies the standard formula: K = 1 − max(R,G,B)/255, then C = (1 − R/255 − K) / (1 − K), and the same for M (green) and Y (blue). Values are shown as percentages, which is what Illustrator, Photoshop, Canva and our print team use.
Why is the converted colour duller than my screen colour?
Screens make colour with light (RGB) and can show more colours than ink on material (CMYK) can reproduce. Bright and neon colours sit outside the printable range, so the closest printable colour is more muted. The preview swatch on this page shows an approximation of that shift; the printed result also depends on the material and machine.
Is this converter the same as Photoshop or Illustrator?
It uses the same basic formula, but Adobe software converts through an ICC colour profile (for example U.S. Web Coated SWOP or ISO Coated), which produces slightly different percentages for the same colour. Treat these values as a starting point and confirm with a printed CMYK chart or a test print.
Can I convert CMYK back to RGB?
Yes, switch the direction toggle. R = 255 × (1 − C) × (1 − K), and the same for G (magenta) and B (yellow). This is useful for showing a printed brand colour on a website.
What CMYK value should I use for black text and large black areas?
Use 0-0-0-100 (plain K) for text and thin lines so they stay sharp. For large solid black areas on signboards and banners use a rich black such as 60-40-40-100 so the panel looks deep black rather than dark grey.
How do I get the exact colour I need on a signboard or banner?
Design in CMYK, print our free CMYK chart on the material you plan to order, and pick from the printed sheet. If the colour must match a brand or an earlier print, tick colour-critical when you order (RM50 per item) and our technician colour-matches to your physical sample and confirms with you before printing.