Developer
RGB to CMYK Converter
Type a HEX or RGB color to get its CMYK ink percentages, convert a whole list at once, or go back from CMYK to RGB.
cmyk(84%, 58%, 0%, 8%)C84 M58 Y0 K8#2563ebrgb(37, 99, 235)Total ink: 150%. This formula ignores ink limits: pure black is K only, and very dark colors can come out close to 300%. A press profile builds dark colors with a controlled mix of all four inks and keeps the total under the paper’s limit (often 300–330% on coated paper, less on uncoated).
Before you send this to a printer
These numbers come from the simple formula design apps show by default. A real conversion uses an ICC profile for the press and paper — for example FOGRA39 (coated paper, Europe) or GRACoL 2006 (coated, US) — and gives different numbers, especially for bright blues, greens and oranges that ink cannot reproduce. For brand colors, ask your printer which profile they use, or convert in a color-managed app.
Need HSL or HSV too? Try the color picker or the color converter.
Processed on your device — nothing is sent anywhere.
Works in your browser. No account needed.
Frequently asked questions
What formula does this converter use?
It uses the standard uncalibrated formula, with no color profile. Black is K = 1 − max(R, G, B), with each channel first divided by 255. Cyan is (1 − R − K) ÷ (1 − K), and magenta and yellow are worked out the same way from green and blue. The results are shown as percentages. Most online converters and web color pickers use this formula. Photoshop and Illustrator are different: they convert with their working CMYK profile, so their numbers will not match.
Will my printed color match these CMYK numbers?
Not exactly. Printers convert colors with an ICC profile for the press, ink and paper, for example FOGRA39 for coated paper in Europe or GRACoL 2006 in the US. A profile changes how much of each ink is used, adds black to dark colors and caps the total ink. Its numbers are often quite different from the simple formula. Use these values as a starting point, and let your print shop or a color-managed app make the final conversion.
Why do bright RGB colors look duller in print?
Screens make color by adding light, and ink makes color by absorbing it. Many saturated screen colors, such as vivid blues, greens and oranges, lie outside what CMYK inks can print. A proper profile moves those colors to the nearest printable color, so they look duller. This page does not show a gamut warning, because it would need the exact profile your printer uses to be accurate.
What is total ink, and why does it matter?
Total ink, also called total area coverage, is C + M + Y + K added together. Presses have a limit, often around 300% for coated paper and lower for uncoated or newsprint, because too much ink smudges and dries slowly. The simple formula ignores that limit: pure black comes out as K only, while very dark colors can come out close to 300%. For large black areas, printers often ask for a rich black such as 60/40/40/100 instead.
Can I convert CMYK back to RGB?
Yes. Open the CMYK → RGB tab and move the sliders or paste four values. The result is the same formula run backwards, so it roughly shows what those inks mean on screen. Rounding to whole percentages loses a little precision. That is why converting RGB to CMYK and back can change a channel by a unit or two.
Is anything sent to a server?
No. All the parsing, conversion and CSV export runs as JavaScript in your browser. Colors you type or paste never leave your device, and the page keeps working offline once it has loaded.
About this tool
This RGB to CMYK converter turns screen colors into the four process inks used in printing: cyan, magenta, yellow and black. Enter a HEX code or RGB values and you get the CMYK percentages in two copy-ready forms, ink bars that show how much of each ink the color needs, and the total ink. There are two more modes. Batch list converts a whole list of brand or palette colors at once and exports a CSV, and CMYK → RGB goes the other way.
The numbers come from the standard uncalibrated formula. Black takes whatever is missing from the brightest channel, and cyan, magenta and yellow make up the rest. It is the same arithmetic most online color tools use, including our color picker. It is honest maths, but it is not a print profile. It does not know your paper, press or ink, so it cannot tell how a color will actually look in print.
Real print jobs use ICC profiles. FOGRA39 and its successor FOGRA51 are common for coated paper in Europe, and GRACoL 2006 and SWOP are used in the US. A profile swaps some cyan, magenta and yellow for black, builds rich blacks, keeps total ink within the press limit, and maps colors that ink cannot reach to the closest printable ones. The same RGB color can therefore give quite different CMYK numbers from two profiles, and both can differ from this formula.
A practical workflow: use this tool to get quick CMYK values for mock-ups, spreadsheets, brand guides and rough briefs. Then, before a paid print run, ask the printer which profile they use, convert your artwork with it in a color-managed app, and ask for a hard proof of any color that matters. For solid brand colors, a Pantone or other spot-color reference is often more reliable than any CMYK build.