HEX to CMYK Converter

HEX to CMYK

This is a HEX to CMYK converter: it turns a web HEX into print cyan, magenta, yellow and black. Screens mix light (RGB); presses mix ink (CMYK). #FF0000 is cmyk(0%, 100%, 100%, 0%). Black is K 100%; white is all zeros. This is not an ICC profile, so a press will not match pixel-for-pixel.

How to use

1. Paste HEX, short #F00, rgb() or cmyk(), or pick a color. Chinese fullwidth commas and a percent sign ％ are accepted.
2. Drag the C, M, Y or K sliders, or type percents 0–100. rgb() and cmyk() update as you type.
3. Click a channel chip to copy C / M / Y / K, HEX or RGB. Copy next to rgb() or cmyk() copies that line. Copy result copies cmyk().
4. Show example loads #FF0000. The swatches fill #FF0000, #000000, #FFFFFF, #DC2626, #16A34A, #2563EB, #3B82F6 and #FF5733.
5. Pick from screen uses the browser EyeDropper where the browser allows it. Batch accepts one color per line or commas. Clear all empties the boxes.

Notes

HEX splits into RGB 0–255, then K = 1 − max(R′, G′, B′) with R′ = R/255. C, M and Y use (1 − channel − K) / (1 − K). When K is 1 (pure black), C, M and Y are 0. Percents keep one decimal. HEX → CMYK → HEX can land one unit off because of that rounding. Invalid HEX shows an error instead of crashing. Related: HEX to RGB, HEX to RGBA, Color Converter.

Where to use it

• Packaging and business-card mockups before a print shop ICC is available.
• Checking a brand red: #FF0000 should read C0 M100 Y100 K0.
• Explaining why a screen blue looks dull on paper.

Questions