RGB to LCH Converter

Convert sRGB red, green, and blue values to CIELCH: lightness, chroma, and a hue angle in degrees. Useful for comparing colors by hue and chroma instead of by RGB channels.

rgb

lch

cielab

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Quick Presets

Common RGB colors for quick conversionNeed LCH to RGB?

Input

Enter RGB values to convert to CIELCH (lightness, chroma, hue).

Red (R)

Green (G)

Blue (B)

How it works: Converts sRGB to CIELCH(ab): RGB to XYZ with the D65 matrix, XYZ to LAB, then chroma as the distance from the neutral axis and hue as an angle in degrees from 0 to 360.

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What is RGB to LCH Converter?

The RGB to LCH Converter turns sRGB channel values into CIELCH. Enter red, green, and blue from 0 to 255, then read lightness L*, chroma C*, and hue angle h in degrees. The preview swatch shows the color you entered.

How does RGB to LCH Converter work?

The conversion starts by linearizing the sRGB channels and multiplying by the D65 matrix to get XYZ. XYZ then converts to CIELAB relative to the D65 white point. LCH is the polar form of that LAB result: chroma is the square root of a* squared plus b* squared, and hue is atan2(b*, a*) in degrees, wrapped to 0 through 360.

Grays have no chroma, so their hue is reported as 0. Chroma for sRGB colors tops out near 134, reached by pure blue at RGB 0, 0, 255.

Key Features

Converts sRGB to XYZ, LAB, and LCH(ab)
Uses the D65 white point
Reports lightness, chroma, and hue angle in degrees
Wraps hue into 0 through 360 and reports 0 for grays
Live preview of the input color
Four preset colors with matching RGB values

Common Use Cases

When and why you might need this tool

Compare colors by hue and chroma
See whether two brand colors share a hue angle and differ only in chroma or lightness.
Find the lightness of a color
Read L* to judge how light a color appears, which RGB channels do not show directly.
Sort a palette perceptually
Convert each swatch and order the list by L*, C*, or h.
Prepare values for an LCH-based tool
Turn RGB values from a style guide into LCH numbers for a color-science workflow.

How to Use This Tool

Step-by-step guide to get the best results

Enter red, green, and blue

Use the sliders or type values from 0 to 255 for each channel.

Check the preview

The swatch shows the color those channels produce.

Read L, C, and h

The result lists lightness, chroma, and hue angle in degrees to two decimals.

Compare presets

Select a preset such as blue or red to see how hue angle changes between colors.

Copy the lch() string

Copy the value into your notes or code.

Pro Tips

1
Pure red sits at a hue near 40 degrees and pure blue near 306 degrees, so hue angles do not follow the RGB wheel order you may expect.
2
Check a gray first. Equal red, green, and blue values return a chroma of 0 and hue 0.
3
Values are D65 LCH. CSS lch() is D50, so a browser reports different numbers for the same color.
4
Keep two decimals when you pass values on. Rounding to whole numbers visibly shifts hue for low-chroma colors.
5
Use the LCH to RGB Converter to go back, accepting a difference of one or two in a channel from rounding.

Frequently Asked Questions

How do I convert RGB to LCH?

Convert sRGB to XYZ, then to CIELAB, then take chroma as the square root of a* squared plus b* squared and hue as the arctangent of b* over a*. This tool does all of it.