RGB to CMYK Converter

What is the difference between RGB and CMYK?

RGB describes red, green and blue light with integer channels from 0 to 255. A HEX code such as #3498DB writes those same channels in hexadecimal. These are common ways to specify screen colors.

CMYK describes cyan, magenta, yellow and black ink percentages. Different printing conditions can use different CMYK mixes for the same screen color; a profile-free conversion is not the one definitive print recipe.

• Start with HEX or RGB when moving a web color.
• Enter an existing ink mix in the CMYK tab to keep its original percentages.

How do I use the workbench?

Select RGB, CMYK or HSL, then edit a numeric field or slider. The swatch and other formats update immediately. You can paste HEX, rgb(...) or cmyk(...) into the code field above the tabs.

• Use the browser color picker to select a color visually.
• Try the red, blue, black or white sample buttons to change the actual input and results.
• Copy one output or choose Copy all values for the full set.

How do HEX and RGB correspond?

The pairs 34, 98 and DB in #3498DB are hexadecimal values 52, 152 and 219. Three-digit #3AD expands to #33AADD by doubling each digit. The leading # is optional when pasting.

RGB fields accept only whole numbers from 0 to 255. An unfinished or invalid code leaves the last valid result visible while the input displays an error.

How is the CMYK estimate calculated?

Divide RGB channels by 255 and set K to 1 − max(R,G,B). When K is 1, black is C/M/Y 0%, K 100%. Otherwise C=(1−R−K)/(1−K), with the same rule for M and Y.

RGB(255, 0, 0) gives C 0%, M 100%, Y 100%, K 0%. #FF8800 is RGB(255, 136, 0) and gives approximately C 0%, M 46.7%, Y 100%, K 0%. Displayed percentages are rounded to one decimal place.

• Computed CMYK is not a printer-specific separation.
• Do not mistake the screen swatch for the color of ink on paper.

Is my entered CMYK mix preserved?

Yes. When you edit CMYK directly, all four input percentages remain unchanged even after the screen color is calculated. More than one ink mix can produce the same approximate RGB result.

For example, C 100%, M 0%, Y 0%, K 100% yields black on screen but remains your original mix. Re-entering black through RGB would calculate C 0%, M 0%, Y 0%, K 100% instead; the tool does not silently replace your CMYK input.

Why might a real print look different?

Ink, paper, printing process and equipment all affect the result. ICC profiles describe specific output conditions for color-managed workflows. This tool does not load a profile, perform gamut mapping, enforce total ink limits or create proofs.

Before preparing a print file, ask the printer about accepted RGB or CMYK files, paper choice, recommended ICC profile and proofing. Some printers prefer to perform the conversion themselves.

• Confirm brand colors and large print runs using the printer’s profile and proof.
• Do not treat this screen swatch as a promise of printed color.

When are HSL and contrast useful?

HSL adjusts screen color by hue, saturation and lightness. Hue ranges from 0 to 360 degrees; saturation and lightness range from 0 to 100%. Editing HSL updates RGB, HEX and CMYK as well.

The black and white text contrast ratios compare text against the current swatch. The higher ratio is suggested, but accessibility also depends on text size, weight and surrounding interface.

Where can I use copied values?

HEX, rgb(...) and hsl(...) can be used in CSS and design notes. The cmyk(...) string is an ink-reference note, not a normal CSS color. Copy all values includes all four formats and an explicit profile-free CMYK warning.

For print instructions, include the file and output conditions agreed with the printer rather than relying on these numbers alone.

• Check the target color space before adding a color to a web project.
• For print handoff, confirm output conditions as well as numeric values.

What if a value looks wrong?

Check ranges first: RGB 0–255 integers; CMYK 0–100% per channel; HSL hue 0–360 and other channels 0–100%. Blank or incomplete inputs leave the last valid result in place until corrected.

If another design app shows different CMYK, compare its document color space and ICC profile first. This tool uses profile-free arithmetic and rounds displayed percentages to one decimal place.