RGB to CMYK converter.

Scale R, G and B to 0 to 1. Black is K = 1 − max(R, G, B); then C = (1 − R − K) ÷ (1 − K), and M and Y the same with G and B. rgb(220 38 38) gives cmyk(0%, 83%, 83%, 14%).

Not for a press. The formula knows nothing about paper or inks, so the printed color will differ, often a lot for vivid blues and greens that ink can't reach. A print shop converts with an ICC profile (FOGRA39 in Europe, GRACoL or SWOP in the US) in a layout or image editor.

For a first idea of the ink mix, for a brand sheet that lists approximate CMYK, or for print-on-demand forms that ask for numbers. For anything that must match, ask for the printer's profile or a proof.

Any CSS color: rgb(), hex, hsl(), oklch() and the rest. Type it in the field at the top or in any row below.

Yes: type cmyk(0%, 83%, 83%, 14%) or four numbers into the CMYK row and the RGB, hex and the rest follow.

No. The conversion runs in your browser.

No. The RGB to CMYK converter is free and opens without a sign-in, an account or an install.

Nothing. The RGB to CMYK converter holds your input in the page's memory, so closing or reloading the tab clears it, and it saves nothing in this browser.

Closest to the RGB to CMYK converter: RGB to HEX converter, Color converter, HEX to RGB converter, RGB to HSL converter. Each opens on its own page, free and in the browser.

The RGB to CMYK converter is one of 17 in its group. The group's page, /tools/color, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.