RGB to CMYK converter

How to convert RGB to CMYK

To convert RGB to CMYK, enter your RGB color in the box above and read the CMYK value next to it. For example, rgb(34, 197, 94) is cmyk(83%, 0%, 52%, 23%). The result updates as you type, and every other format (HEX, RGB, HSL, CMYK and more) is shown at the same time.

What RGB and CMYK mean

RGB describes a color as amounts of red, green and blue light, each from 0 to 255. rgb(59, 130, 246) is the same color as #3B82F6. CSS also accepts an opacity value, as in rgba(59, 130, 246, 0.5).

CMYK is the ink model used in printing: percentages of cyan, magenta, yellow and black. Screens cannot show every CMYK color exactly and printers differ, so a conversion from RGB is an approximation to use as a starting point.

Convert RGB to CMYK by hand

Here is the calculation for rgb(34, 197, 94), step by step:

1. Divide each channel by 255 and take the largest: K = 1 − max = 23%.
2. Then C = (1 − R − K) ÷ (1 − K) = 83%, M = (1 − G − K) ÷ (1 − K) = 0% and Y = (1 − B − K) ÷ (1 − K) = 52%.
3. Result: cmyk(83%, 0%, 52%, 23%).

RGB to CMYK table of common colors

When to use RGB and when CMYK

RGB is the model screens use and the one CSS functions such as rgba() build on, which makes it handy when you need transparency or want to compute colors in code. CMYK matters when a color will be printed. Use it as a starting point and always check a physical proof, because inks and paper change the result.

Good to know

• Shorthand HEX codes such as #38F expand to #3388FF, and eight-digit codes carry an opacity value at the end.
• Values are rounded to whole numbers for display; the converter keeps more precision internally.
• The color picker lets you pick a color by eye when you do not have its code.
• Colors displayed on screen depend on your monitor's calibration, so the same code can look slightly different on different devices.