RGB to CMYK converter
Convert RGB screen colors to CMYK percentages.
Example: rgb(255, 107, 53)
Convert RGB screen colors to CMYK percentages.
Example: rgb(255, 107, 53)
A quick estimate for when a print brief, packaging spec or sign shop asks for CMYK and you only have the RGB values from your design. The numbers come from the standard formula: K = 1 − max(R, G, B), and then C, M and Y are scaled from what is left.
About the formats. RGB gives the amount of red, green and blue light as three numbers from 0 to 255, as in rgb(255, 107, 53). Both the comma form and the space form rgb(255 107 53 / 50%) are read, and percentages work too. CMYK describes a color as the share of cyan, magenta, yellow and black ink (each 0% to 100%) used to print it. Values are read as percentages, with or without the % sign, and the CSS name device-cmyk() is understood too.
How exact is it? RGB channels are read as they are and rounded to the nearest whole number when they carry decimals, so a normal rgb() value is never altered. The conversion uses the plain mathematical formula with no color profile, so treat the percentages as an estimate. Vivid screen colors fall outside what ink can print and will look duller on paper.
For example, rgb(142, 202, 230) in RGB is cmyk(38.3%, 12.2%, 0%, 9.8%) in CMYK. Treat the result as a starting point. Strongly saturated RGB colors, like bright cyan or electric green, fall outside what CMYK ink can reproduce and will print duller than they look on screen. A proof from your printer is the only reliable check.
Type or paste an RGB value such as rgb(142, 202, 230) and the CMYK value, cmyk(38.3%, 12.2%, 0%, 9.8%), appears straight away. Use Copy to put it on your clipboard, or choose a color with the picker.
Divide each channel by 255, set K to 1 minus the largest of the three, then C = (1 − R − K) ÷ (1 − K), and the same for M with G and Y with B. The results are shown as percentages.
Each channel is its own share of ink coverage, so they do not need to total 100. Printers do limit the total ink on the paper, often to 240 to 300%, which a color profile takes care of.
RGB channels are read as they are and rounded to the nearest whole number when they carry decimals, so a normal rgb() value is never altered. The conversion uses the plain mathematical formula with no color profile, so treat the percentages as an estimate. Vivid screen colors fall outside what ink can print and will look duller on paper.
CMYK has no transparency, so any transparency in the RGB value is left out of the result. The preview still shows the color with its transparency.
No. The conversion runs in your browser and nothing is uploaded.