CIELAB Color Calculator

Professional color science tool for converting between RGB, HEX, CIELAB (L*a*b*), and XYZ color spaces with precise mathematical accuracy. Essential for color quality control, Delta E calculations, and achieving perceptual color uniformity across different devices and media with D65 illuminant standard.

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Quick Presets

Common colors for quick conversion

Input

Enter color values in RGB, CIELAB, or HEX format

RGB Values (0-255)

Red

Green

Blue

How it works: Converts between RGB, CIELAB, and XYZ color spaces using the sRGB to XYZ matrix with D65 illuminant. CIELAB is perceptually uniform — equal numerical differences correspond to equal visual differences.

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What is CIELAB Color Calculator?

CIELAB color calculator converts colors between CIELAB, RGB, and XYZ spaces using D65 sRGB conversion math. Enter RGB, hex, XYZ, or LAB values to get six-decimal L*, a*, and b* output. The tool also calculates Delta E color difference between two LAB colors for print, design, and quality checks.

How does CIELAB Color Calculator work?

This tool implements the standard CIE color space conversion formulas. It converts RGB to XYZ using the sRGB transfer function and D65 illuminant, then XYZ to LAB using the reference white point. The reverse conversions are also supported. Delta E (CIE76) is calculated as the Euclidean distance between two LAB points.

Key Features

Converts RGB to LAB and LAB to RGB
Converts XYZ to LAB and LAB to XYZ
Calculates Delta E (CIE76) between two LAB values
Uses D65 illuminant and sRGB color space
Shows L*, a*, b* components individually
Copy values to clipboard
Accepts hex input and converts through RGB, XYZ, and LAB
Six decimal place precision

Common Use Cases

When and why you might need this tool

Measuring color difference
Calculate the Delta E between two colors to determine how perceptibly different they are.
Print color matching
Convert RGB screen colors to LAB for accurate print color matching.
Color science research
Work with LAB values for experiments requiring a perceptually uniform color space.
Quality control in manufacturing
Compare production color samples against a target using Delta E values.

How to Use This Tool

Step-by-step guide to get the best results

Enter a color

Input an RGB hex code or LAB values.

Convert

The tool converts between color spaces and shows all representations.

Compare two colors

Enter two LAB values to calculate the Delta E difference.

Copy values

Copy the LAB, RGB, or XYZ values you need.

Pro Tips

1
Delta E below 1 is imperceptible. 1-2 is barely noticeable. Above 3 is clearly visible.
2
L* represents lightness (0=black, 100=white). a* is green-red axis. b* is blue-yellow axis.
3
LAB is perceptually uniform: equal numerical distances represent equal perceived differences.
4
Use LAB when you need to measure color differences, not just represent colors.
5
RGB to LAB does not happen directly. The tool linearizes the sRGB input, converts to XYZ using the D65 reference white, then converts XYZ to LAB. Hex codes follow the same path through RGB.

Frequently Asked Questions

What is CIELAB?

CIELAB (L*a*b*) is a color space designed to be perceptually uniform. Equal distances in LAB space correspond to roughly equal perceived color differences. It is widely used in color science and print.

What is Delta E?

Delta E is a single number representing the total color difference between two colors in LAB space. A Delta E below 1 is generally imperceptible to the human eye.

Is my data sent to a server?

No. The CIELAB color calculator performs conversions locally in the browser. Nothing is transmitted.

What illuminant is used?

The tool uses the D65 illuminant, which represents average daylight and is the standard for sRGB.

Can I convert hex to LAB?

Yes. Enter a hex color code and the tool converts it through RGB to XYZ to LAB.

What is the difference between CIE76 and CIEDE2000?

CIE76 is the original Delta E formula: a straight Euclidean distance between two LAB points. It overestimates differences in saturated colors and underestimates them in dark blues. CIEDE2000 fixes those issues with weighting terms for hue, chroma, and lightness, at the cost of a much more complex calculation. This calculator outputs CIE76 Delta E.

How do you calculate Delta E by hand?

For two LAB colors (L1, a1, b1) and (L2, a2, b2), the CIE76 Delta E is the square root of (L1-L2) squared plus (a1-a2) squared plus (b1-b2) squared. For example, LAB (50, 10, 0) and LAB (52, 12, -1) give a Delta E of sqrt(4 + 4 + 1) = 3.0, which is clearly visible to most observers. CIEDE2000 requires additional angular hue and chroma weighting terms and is rarely computed by hand.