RGB to CMYK Converter: RGB Color to CMYK

What is RGB to CMYK Converter: RGB Color to CMYK?

This RGB to CMYK converter turns an RGB color into its CMYK (Cyan, Magenta, Yellow, Key/black) equivalent, the color model used in print, with a live swatch and the matching hex code shown alongside. Enter R, G, and B as 0-255 values and the CMYK percentages update instantly as you type. This uses the standard device-independent formula for converting screen (additive, RGB) color to print (subtractive, CMYK) color, which is the best you can do without a specific printer and paper profile. It is not a match to any particular printer's actual output. Everything runs entirely in your browser; nothing you enter is sent to a server.

RGB to CMYK Reference Table

How to Use the RGB to CMYK Converter

1. 1

   Enter R, G, and B: Type values from 0 to 255 for red, green, and blue.

2. 2

   Read the CMYK Result Instantly: The CMYK percentages, hex code, and a live swatch appear automatically.

3. 3

   Copy the Result: Use the copy button to copy the CMYK values for a print spec.

RGB to CMYK Conversion Formula

K = 1 − max(R/255, G/255, B/255), then C = (1−R/255−K) / (1−K), M = (1−G/255−K) / (1−K), Y = (1−B/255−K) / (1−K), each rounded to a whole-number percentage. K captures how dark the color is (how far its brightest channel is from full white), and C/M/Y capture how much of each remaining ink is needed once that darkness is factored out. This is the reverse of the formula used by CMYK to RGB Converter. The two tools always agree on the same color, aside from the rounding CMYK's whole-percentage display introduces.

How to Convert RGB to CMYK

Worked example: web green, RGB(0, 128, 0). K = 1 − max(0, 128/255, 0) = 1 − 0.502 = 0.498 → 50% C = (1 − 0 − 0.498) / (1 − 0.498) = 1.0 → 100% M = (1 − 0.502 − 0.498) / (1 − 0.498) = 0 → 0% Y = (1 − 0 − 0.498) / (1 − 0.498) = 1.0 → 100% Result: C=100, M=0, Y=100, K=50.