CMYK to RGB Converter
Bring print CMYK percentages back to screen RGB and HEX — instantly, with the formula shown and clear notes on when the round trip loses information. Runs 100% in your browser.
Accepts cmyk(c, m, y, k) with percentages or 0–1 values.
Enter a color to see every format.
Reversing the ink math
Where RGB→CMYK extracts a black component, the reverse direction folds it back in. With C, M, Y, K as fractions from 0 to 1, each screen channel is the leftover light after its opposing ink and the shared black have absorbed their share:
R = 255 × (1 − C) × (1 − K)
G = 255 × (1 − M) × (1 − K)
B = 255 × (1 − Y) × (1 − K) Worked example with cmyk(73%, 49%, 0%, 23%): the black factor is 1 − 0.23 = 0.77. Red becomes 255 × (1 − 0.73) × 0.77 ≈ 53, green 255 × (1 − 0.49) × 0.77 ≈ 100, and blue 255 × (1 − 0) × 0.77 ≈ 196 — so the screen equivalent is rgb(53, 100, 196), hex #3564c4.
Why the round trip isn’t always lossless
Converting RGB → CMYK → RGB with the naive formulas returns your exact color, because the black extraction is designed to invert cleanly. The loss appears in the other direction and in the real world:
- Redundant ink builds. Different CMYK combinations can map to the same RGB —
cmyk(0%, 0%, 0%, 50%)andcmyk(50%, 50%, 50%, 0%)both land near the same gray on screen. Going back, a converter has to pick one spelling and usually maximizes K. - Profile reality. Numbers from a print PDF were produced under a specific ICC profile (FOGRA, GRACoL…). The naive formula ignores dot gain and ink behavior, so on-screen previews are approximations of what the press does.
- Gamut direction matters. CMYK → RGB is safe (every printable color has a screen representation), but the reverse clips: vivid screen colors have no ink equivalent.
Additive vs subtractive, in one table
| RGB (screens) | CMYK (print) | |
|---|---|---|
| Model | Additive — starts black, adds light | Subtractive — starts white, absorbs light |
| Channels | Red, Green, Blue (0–255) | Cyan, Magenta, Yellow, Key/black (0–100%) |
| “All channels full” | White | Muddy near-black (why K exists) |
| Gamut | Larger (vivid cyans/greens possible) | Smaller, paper-and-ink dependent |
| Typical use | Web, apps, video | Brochures, packaging, magazines |
When you actually need this direction
- Rebuilding a website from a printed brand manual that only lists CMYK values.
- Previewing how a print spec will roughly look on screen before ordering a proof.
- Digitizing older logos and stationery whose sources are prepress files.
- Cross-checking that a designer’s “same blue” in print and web really is the same family.
Everything runs locally — the values never leave your browser. Heading the other way? Use the RGB to CMYK converter; and to check whether a converted brand color still reads well as text, run the pair through the contrast checker.
Frequently asked questions
How do I convert CMYK to RGB by hand?
Turn the percentages into fractions, then multiply: each RGB channel is 255 × (1 − its opposing ink) × (1 − K). For cmyk(73%, 49%, 0%, 23%) that gives rgb(53, 100, 196).
Why do two different CMYK values give the same RGB?
CMYK has four channels for three dimensions of color, so ink builds overlap — gray made from pure K and gray made from equal C+M+Y can look identical on screen. The extra channel exists for printing economics and quality, not for extra colors.
Will the RGB result match my printed sample exactly?
Only approximately. Printed color depends on the ICC profile, paper and ink density. The formula here is the standard device-independent approximation — good for orientation, not a proofing system.
Can every CMYK color be shown in RGB?
Practically yes — the printable gamut fits inside what screens can show, so this direction does not clip. The lossy direction is RGB to CMYK, where vivid screen colors have no ink equivalent.
What is a typical CMYK value for pure white and pure black?
White is 0/0/0/0 — no ink at all, the paper itself. Black in body text is 0/0/0/100; large areas often print a “rich black” with added C/M/Y for depth.
Is anything uploaded when I convert?
No. This converter runs 100% in your browser and works offline once loaded.