Use this CMYK to RGB Converter to convert CMYK values to RGB, hex, or back again — instantly, with no signup required.
CMYK
RGB
How It Works
CMYK to RGB conversion uses a fixed math formula, not a lookup table. For each channel, RGB = 255 × (1 − color%) × (1 − black%). So Red = 255 × (1 − C) × (1 − K), Green = 255 × (1 − M) × (1 − K), and Blue = 255 × (1 − Y) × (1 − K), with C, M, Y, and K expressed as decimals (0–1).
Converting the other direction — RGB to CMYK — starts by finding K, the black value: K = 1 − max(R, G, B), using RGB values scaled to 0–1. From there, C = (1 − R − K) ÷ (1 − K), and M and Y follow the same pattern using G and B.
This formula is a standard, uncalibrated conversion — the same math used by most browser-based tools and design software’s quick-preview mode. It’s built for screen and web design work: matching a CMYK value from a print file to a usable RGB or hex code for CSS, mockups, or on-screen branding.
It is not a color-managed, ICC-profile-based conversion. Real printers apply a specific color profile (like US Web Coated SWOP or a press-specific ICC profile) that shifts the output based on ink, paper, and press calibration — two printers can produce visibly different colors from the identical CMYK values. If you need press-accurate color matching, use a Pantone bridge guide or your printer’s proofing tools instead of any browser-based converter, this one included.
When to Use This
- Matching a client’s print branding to their website. Freelancers and agencies often receive a logo or brand guide with CMYK values from a print designer, and need the closest RGB/hex equivalent for the WordPress theme’s color settings, buttons, and CSS.
- Sanity-checking a design handoff. Before dropping a CMYK-sourced color into a stylesheet, converting it confirms what it will actually look like on screen — CMYK values can render noticeably different on a monitor than they do on paper.
- Quick reference during a build. No install, no account — paste values, get RGB and hex immediately, copy straight into your CSS or theme customizer.
FAQ
How do I convert CMYK to RGB?
Multiply each RGB channel by (1 − color percentage) and (1 − black percentage), then scale to 255. For example, R = 255 × (1 − C) × (1 − K). Enter your C, M, Y, K values above and the tool calculates this instantly, alongside the matching hex code.
Is CMYK to RGB conversion accurate for print matching?
Not for press-accurate matching. This converter uses a standard uncalibrated formula suited for screen/web use — real print output depends on the specific ICC color profile, ink set, and paper used by the printer, which this tool doesn’t account for. For color-critical print work, check against a physical Pantone bridge guide or your printer’s proofing process instead.
Can I convert a CMYK image to RGB online?
Not reliably through a browser-based tool. Browsers decode images using RGB by default, and true CMYK image files (common in print-ready JPEGs and TIFFs from designers) often render with incorrect or inverted colors when opened directly in a browser. For accurate image conversion, use desktop software like Photoshop, GIMP, or a dedicated image-conversion tool that reads embedded color profiles correctly — this converter is built for individual color values, not image files.
What’s the difference between CMYK and RGB?
CMYK (Cyan, Magenta, Yellow, Key/Black) is a subtractive color model used for print, where colors are created by layering ink that absorbs light. RGB (Red, Green, Blue) is an additive color model used for screens, where colors are created by combining light. The same color can look different across the two models because they’re fundamentally different systems, not simple opposites.
Why don’t my converted RGB values look exactly like the printed color?
Because this is a mathematical approximation, not a color-managed conversion. Print colors are also affected by the physical ink, paper stock, and printer calibration — factors no formula-based converter can account for. Treat the RGB/hex output here as a close starting point for web design, not a guaranteed print match.