CMYK to RGB Colour Converter

How it works

Write one colour per line; the notation is recognised from the line itself, so there is no direction to choose. Four numbers are read as CMYK: the "0 54 88 40" a print shop sends you, cmyk(0, 54, 88, 40), the percent form cmyk(0%, 54%, 88%, 40%) and the C0 M54 Y88 K40 notation used in design software all mean the same thing. Three numbers or rgb(154, 52, 18) are read as RGB, and a HEX code such as #2F6FED is accepted directly. For example, the orange a brand guide lists as "C0 M54 Y88 K40" comes out as rgb(153, 70, 18) and #994612 — that HEX code is what you put on the website. In the other direction, pasting the blue #2F6FED gives cmyk(80%, 53%, 0%, 7%), the percentages you would use in a file going to print. With the output format set to "All", each line starts with the counterpart of what you typed, followed by the other notations. Lines that cannot be read are marked in the output so you can see which one is wrong. The conversion is a formula and applies no print profile (ICC); the result can therefore differ by a few units from what Photoshop or Illustrator shows, which is explained below.

This tool is also known as cmyk to rgb, rgb to cmyk, cmyk to rgb converter, cmyk to hex, convert cmyk to rgb, cmyk colour code to rgb.

What is CMYK?

CMYK names the four inks used in printing: Cyan, Magenta, Yellow and Key (black). Each value states what percentage of that ink is laid on the paper; in cmyk(0, 54, 88, 40) there is no cyan at all and 40 percent black. Because adding ink makes a colour darker, this is a subtractive model — the opposite of a screen. Print shops, brand guides and every PDF sent to press describe colour in this language, while a screen cannot display CMYK directly and has to convert it to RGB first.

What is RGB?

RGB describes how a screen makes colour: the intensity of red, green and blue light on a scale from 0 to 255. Adding light makes the colour brighter, and all three at 255 give white, which is why it is called an additive model. Websites, slides and phone screens understand RGB only. To see how a print colour will look on screen, its CMYK percentages are first converted to RGB — and the swatch on this page shows exactly that RGB equivalent, because a browser paints with light, not ink.

What is HEX colour code?

A HEX code is the RGB value written compactly in hexadecimal: #994612 is exactly the same colour as rgb(153, 70, 18). Read it in pairs: red sits in digits one and two, green in three and four, blue in five and six. Because colour travels in this form through CSS and design tools, the tool writes the HEX code next to every CMYK result; it is the value you copy when handing a colour to a web team. A HEX code carries no CMYK information, so producing CMYK from it again means a formula or a print profile.

What is the difference between CMYK and RGB?

RGB works with light, CMYK with ink. A screen produces colour by adding red, green and blue light: all three at full strength give white, all three at zero give black. Printing lays cyan, magenta, yellow and black ink on white paper and so takes light away; more ink means a darker colour. Because the two models describe the same colour by different routes, they do not map one to one: the bright turquoise or vivid purple of a screen prints duller, and some deep tones of paper do not quite hold on a screen. That is why any converter's result is an approximation — for critical work, a printed proof and the printer's profile have the last word.

Why Photoshop shows slightly different numbers

This tool converts by formula: the K value is derived from the lightest channel and the remaining three channels are scaled against it. Photoshop, Illustrator and InDesign convert through a print profile instead — U.S. Web Coated (SWOP) in the North American colour settings, Coated FOGRA39 in the European ones. A profile accounts for the paper's whiteness and the real colour of the inks, so the same RGB value produces percentages that differ by a few units there.

In practice there are two situations. If you need the closest screen colour to a print value for a website or a slide, the formula result is enough; the eye cannot tell the difference. If you are setting the CMYK percentages for a file that goes to press, the source should be the brand guide or the figures your printer gave you; the RGB → CMYK output here is a starting point and should be checked against the profile your printer works with.

Which value goes where

CMYK says how much of each ink is laid on the paper, as a percentage; it only means something in printed work. RGB and HEX describe the light of a screen, and that is what a website, a presentation, a social-media image or an app interface asks for. If a logo reached you in CMYK only, it needs this conversion before it goes on the web — and the reverse is just as true.

Every RGB colour can be shown on a screen, but not every one can be printed: bright turquoise, vivid purple and saturated green come out duller in CMYK. This tool does not warn when a colour falls outside the printable range, and the swatch always shows the screen colour. For a critical brand colour, a printed proof is the only reliable check.

• Print shop, brochure, business card → CMYK percentages
• Website, CSS, slides, social media → HEX or RGB
• Brand guide → usually lists both; fill in the missing one here

Frequently asked questions

How do I convert a CMYK colour to RGB?

Write the four CMYK percentages on one line — "0 54 88 40" or cmyk(0, 54, 88, 40) — and set the output format to RGB. The result appears as rgb(153, 70, 18) with the colour shown in a swatch next to it. Leave the format on "All" if you also want the HEX code.

Why does Illustrator give different CMYK percentages for the same RGB?

Illustrator and Photoshop apply the print profile set in their colour settings (U.S. Web Coated SWOP or Coated FOGRA39, depending on the region); this tool converts by formula without a profile. The difference is a few units for most colours. For the exact percentages of a print job, check against the profile your printer uses.

Do I have to type the percent signs?

No. 0 54 88 40, cmyk(0, 54, 88, 40) and cmyk(0%, 54%, 88%, 40%) are read the same way, and the C0 M54 Y88 K40 notation is accepted as well. Values must be between 0 and 100; a line outside that range is not silently clipped but marked as not recognised.

Can I convert several colours at once?

Yes. Write one colour per line; each line is read on its own, so CMYK and RGB can be mixed in the same list. The results come back in the same order, so you can convert a whole palette in one go and copy it.