RGB to CMYK Converter

Pick a color or type its red, green and blue values to get the four CMYK percentages, the combined cmyk() value and the total ink coverage.

Runs in your browserFree, no sign-upLast reviewed October 8, 2026

Colour

#4f46e5

CMYK

Cyan: 66%
Magenta: 69%
Yellow: 0%
Key (black): 10%
Combined: cmyk(66%, 69%, 0%, 10%)
Total ink: 145%; Most presses cap this near 300%

Screen colour vs the rounded CMYK value

RGB in

CMYK back

This is the standard arithmetic conversion, not a colour-managed one. A real print job applies an ICC profile for the specific paper and press, so treat these percentages as a starting point and always check a proof before a large run.

Quick answers

How do I convert RGB to CMYK?: Divide R, G and B by 255. K is 1 minus the largest. C = (1 - R - K) / (1 - K), M = (1 - G - K) / (1 - K) and Y = (1 - B - K) / (1 - K). Multiply by 100 for percentages. rgb(255, 165, 0) is cmyk(0%, 35%, 100%, 0%).
What is rgb(0, 0, 0) in CMYK?: cmyk(0%, 0%, 0%, 100%): black ink only, with a total ink coverage of 100%. The formula never adds cyan, magenta or yellow to black, so it will not give you a rich black. Ask your printer for their rich black values if you need a deeper one.
What is white in CMYK?: cmyk(0%, 0%, 0%, 0%). White in print means no ink, so the paper shows through. rgb(255, 255, 255) and #ffffff both convert to four zeros, with total ink coverage of 0%.
Can I convert a hex code to CMYK?: Yes. Leave Read colour from on The colour picker and type your hex code in the box beside the Colour swatch. #4f46e5 gives cmyk(66%, 69%, 0%, 10%) and #ff5733 gives cmyk(0%, 66%, 80%, 0%). A hex code is RGB written in base 16, so the conversion is the same.
Is an online RGB to CMYK conversion accurate enough for print?: It is accurate arithmetic but not a color-managed conversion. Real print values depend on the paper, inks and press, described by an ICC profile, and the same RGB color gets different CMYK numbers under different profiles. Use these figures for estimates and brand sheets, and convert final artwork with the printer's profile.
What does total ink coverage mean?: It is the four CMYK percentages added together, from 0% for bare paper up to a theoretical 400%. Navy, cmyk(100%, 100%, 0%, 50%), has a total of 250%. Presses set a maximum, often somewhere around 300%, because too much wet ink dries slowly and smudges.

What RGB to CMYK Converter does

This RGB to CMYK converter takes a screen color, chosen with a picker or entered as three numbers from 0 to 255, and returns cyan, magenta, yellow and key (black) as whole percentages. rgb(255, 0, 0) is cmyk(0%, 100%, 100%, 0%); rgb(0, 0, 0) is cmyk(0%, 0%, 0%, 100%). It also adds the four figures into a total ink coverage percentage, the number a printer checks against the press limit. The math is the standard formula with no color profile, so the result is a starting point for print, not a press-ready value. Two swatches show your color beside the same color rebuilt from the rounded percentages.

RGB to CMYK chart for common colors

Values returned by this converter. CMYK is listed as cyan, magenta, yellow, black. Lime and Green are the CSS names for #00ff00 and #008000.

Color	RGB	Hex	CMYK	Total ink
Black	0, 0, 0	#000000	0%, 0%, 0%, 100%	100%
White	255, 255, 255	#ffffff	0%, 0%, 0%, 0%	0%
Red	255, 0, 0	#ff0000	0%, 100%, 100%, 0%	200%
Lime	0, 255, 0	#00ff00	100%, 0%, 100%, 0%	200%
Blue	0, 0, 255	#0000ff	100%, 100%, 0%, 0%	200%
Cyan	0, 255, 255	#00ffff	100%, 0%, 0%, 0%	100%
Magenta	255, 0, 255	#ff00ff	0%, 100%, 0%, 0%	100%
Yellow	255, 255, 0	#ffff00	0%, 0%, 100%, 0%	100%
Orange	255, 165, 0	#ffa500	0%, 35%, 100%, 0%	135%
Gold	255, 215, 0	#ffd700	0%, 16%, 100%, 0%	116%
Pink	255, 192, 203	#ffc0cb	0%, 25%, 20%, 0%	45%
Brown	165, 42, 42	#a52a2a	0%, 75%, 75%, 35%	185%
Maroon	128, 0, 0	#800000	0%, 100%, 100%, 50%	250%
Green	0, 128, 0	#008000	100%, 0%, 100%, 50%	250%
Navy	0, 0, 128	#000080	100%, 100%, 0%, 50%	250%
Purple	128, 0, 128	#800080	0%, 100%, 0%, 50%	150%
Teal	0, 128, 128	#008080	100%, 0%, 0%, 50%	150%
Sky blue	135, 206, 235	#87ceeb	43%, 12%, 0%, 8%	63%
Royal blue	65, 105, 225	#4169e1	71%, 53%, 0%, 12%	136%
Mid gray	128, 128, 128	#808080	0%, 0%, 0%, 50%	50%
Silver	192, 192, 192	#c0c0c0	0%, 0%, 0%, 25%	25%
Dark gray	51, 51, 51	#333333	0%, 0%, 0%, 80%	80%

Grays come out as black ink only, because equal red, green and blue leave nothing for cyan, magenta or yellow in this formula. Design software using an ICC profile will usually build the same grays from all four inks.

RGB to CMYK formula

R' = R / 255, G' = G / 255, B' = B / 255. K = 1 - max(R', G', B'). C = (1 - R' - K) / (1 - K). M = (1 - G' - K) / (1 - K). Y = (1 - B' - K) / (1 - K). If K = 1 (pure black), C, M and Y are 0.

Worked for rgb(79, 70, 229), which is #4f46e5. R' = 0.310, G' = 0.275, B' = 0.898. The largest is 0.898, so K = 1 - 0.898 = 0.102, or 10%. C = (1 - 0.310 - 0.102) / 0.898 = 0.655, or 66%. M = (1 - 0.275 - 0.102) / 0.898 = 0.694, or 69%. Y = (1 - 0.898 - 0.102) / 0.898 = 0. The result is cmyk(66%, 69%, 0%, 10%), with total ink of 145%. Because K is set by the brightest channel, that channel's ink is always 0%: every result has at least one of cyan, magenta or yellow at zero.

Worked RGB and hex to CMYK examples

The two swatches are labelled RGB in and CMYK back. The hex codes quoted for them below are what each swatch's copy button gives.

A bright orange-red typed as numbers

Read colour from: The R/G/B numbers. Red 255, Green 87, Blue 51

Cyan 0%, Magenta 66%, Yellow 80%, Key (black) 0%. Combined cmyk(0%, 66%, 80%, 0%). Total ink 146%. Swatches: RGB in #ff5733, CMYK back #ff5733.

A corporate dark blue from a hex code

Read colour from: The colour picker. Colour #003366

Cyan 100%, Magenta 50%, Yellow 0%, Key (black) 60%. Combined cmyk(100%, 50%, 0%, 60%). Total ink 210%.

The default indigo

Colour #4f46e5

Combined cmyk(66%, 69%, 0%, 10%). Total ink 145%. Swatches: RGB in #4f46e5, CMYK back #4e47e6.

The one-step difference between the swatches comes from rounding each ink to a whole percent.

A very dark blue with heavy coverage

Colour #000033

Combined cmyk(100%, 100%, 0%, 80%). Total ink 280%.

Dark, saturated colors give the highest totals. This one is close to the limit many printers set.

A sea green

Colour #2e8b57

Combined cmyk(67%, 0%, 37%, 45%). Total ink 149%. Swatches: RGB in #2e8b57, CMYK back #2e8c58.

What the two swatches do and do not show

The RGB in swatch is the color you entered. The CMYK back swatch is the result of taking the four rounded percentages and converting them to RGB again with the reverse formula, R = 255 x (1 - C) x (1 - K), and likewise for green with M and blue with Y. Any gap between the two is rounding loss. It is usually one step in a channel, and often nothing at all: #ffa500 comes back as #ffa600, #1a1a1a comes back as #191919, and #ff5733 comes back unchanged.

The swatches are not a print preview. A screen makes color by emitting red, green and blue light, while a press lays ink on paper that absorbs light, and the range of colors ink can reach is smaller. Vivid blues, greens and oranges on screen often have no ink equivalent and print duller. This tool cannot show that shift, because it depends on the specific paper and inks. Soft proofing in design software with the printer's ICC profile, or a physical proof, is the way to see it.

Total ink coverage and why this formula tops out at 300%

Total ink is cyan plus magenta plus yellow plus black. Printers publish a maximum for each paper type, commonly somewhere between about 240% and 320%, with uncoated and newsprint stocks at the lower end. Going over it risks slow drying, ink transferring to the next sheet, and muddy shadows. The tool's own hint reads Most presses cap this near 300%; your printer's figure is the one that counts.

With this formula at least one of the three colored inks is always 0%, so the total can never go above 300%, and it only touches that figure for colors one step away from black, such as rgb(0, 0, 1), where black rounds up to 100% while two colored inks are also at 100%. Among usable colors the heaviest results come from dark saturated ones: #000033 and #330000 both total 280%, and dark green #006400 totals 261%. Neutral colors go the other way. Pure black is 100% K with nothing under it, and dark grays are a single ink too.

That matters for large black areas. Black ink alone can look washed out when printed across a big solid, so printers often specify a rich black that adds some cyan, magenta and yellow under the black. The mix varies by printer and paper, and it cannot be derived from an RGB value, so ask for their numbers and enter them directly in your layout software.

Before you send CMYK values to a printer

Ask which ICC profile and total ink limit the printer uses, and convert the final artwork with that profile in your design software.
Use the percentages from this page for quotes, brand guidelines drafts and quick checks, and label them as approximate.
For a color that must match exactly across jobs, such as a logo, ask about a spot color instead of a CMYK mix.
Keep small text and thin lines in black ink only, cmyk(0%, 0%, 0%, 100%), so slight misalignment between plates does not blur them.
Request a proof for any large or expensive run. It is the only reliable check of how the color looks on the actual paper.

Using RGB to CMYK Converter

1
Choose where the color comes from in Read colour from: The colour picker or The R/G/B numbers.
2
If you chose the picker, set the Colour field with the swatch or type a hex code in the box beside it. If you chose the numbers, enter Red, Green and Blue, each from 0 to 255.
3
Read Cyan, Magenta, Yellow and Key (black) in the CMYK panel, or copy the Combined line.
4
Check Total ink against the limit your printer has given you.
5
Compare the RGB in and CMYK back swatches to see how much the rounding to whole percentages moved the color.

Common questions

I typed RGB numbers but the result did not change. Why?

Read colour from is still set to The colour picker, which is the default. Switch it to The R/G/B numbers and the Red, Green and Blue fields take over. With the picker selected, the three number fields are ignored.

Can it convert CMYK back to RGB?

Not from CMYK input. There are no fields for entering ink percentages; the tool only goes from RGB or hex to CMYK. The reverse formula is R = 255 x (1 - C) x (1 - K), G = 255 x (1 - M) x (1 - K) and B = 255 x (1 - Y) x (1 - K), with the percentages written as fractions.

Why do other tools or Photoshop give different CMYK numbers?

They are probably using a color profile. A profile-based conversion accounts for a particular press and paper, replaces some colored ink with black in its own way, and adjusts colors that ink cannot reproduce. The plain formula used here does none of that, so the numbers differ, sometimes by a lot for grays and dark colors.

What does the K in CMYK stand for?

Key. In four-color printing the black plate is the key plate, the one that carries the detail and that the other plates are lined up against. Using K also avoids confusion with B for blue.

Why does my printed color look duller than on screen?

Ink on paper covers a smaller range of colors than a backlit screen, and the brightest, most saturated screen colors fall outside it. They are replaced with the nearest printable color, which is less intense. Paper type matters too: uncoated paper absorbs ink and mutes color more than coated paper.

Are the percentages rounded?

Yes, each ink is rounded to a whole percent, and Total ink is the sum of the four rounded figures. Whole percentages are what print specifications normally use. The CMYK back swatch shows how little the rounding changes the color.

Should I design in RGB or CMYK?

For screens, RGB. For a job that will only be printed, set the document up in CMYK with the printer's profile from the start. For work used in both places, many designers keep an RGB master and convert a copy for print, checking the important colors by proof.