CIELAB Color Calculator
Convert between LAB, sRGB, and XYZ, then estimate color difference using Delta E (1976).
1) LAB → RGB / HEX / XYZ
2) RGB → LAB / XYZ
3) Delta E (CIE76)
What is the LAB color space?
The LAB color space (also called CIELAB) is a device-independent way to represent color. Unlike RGB, which depends on a display, LAB is designed so that equal numeric changes are closer to equal visual changes. That is why LAB appears in print workflows, image processing pipelines, and color quality control systems.
In LAB, each color is represented by three values:
- L*: lightness from black (0) to white (100)
- a*: green (negative) to red (positive)
- b*: blue (negative) to yellow (positive)
Why use a LAB color space calculator?
When working across digital screens, printers, scanners, and cameras, color conversion matters. A LAB calculator helps you translate values between systems and evaluate whether two colors are perceptually close.
Common use cases
- Converting measured LAB values from a spectrophotometer into display RGB previews
- Checking Delta E tolerance during packaging or textile production
- Comparing brand colors across print and web outputs
- Validating whether an sRGB color sits inside or outside a target color gamut
How this calculator works
This page uses standard conversion math between CIELAB, XYZ, and sRGB with a D65 white point. The conversion flow is:
- LAB → XYZ using CIE nonlinear transform
- XYZ → linear RGB through matrix multiplication
- linear RGB → sRGB through gamma companding
For the reverse direction, the sequence is inverted: sRGB is linearized, transformed to XYZ, then converted to LAB. If LAB converts to out-of-range RGB values, the tool clamps values to 0–255 and warns that the original color is outside the sRGB gamut.
Understanding Delta E
Delta E (ΔE) is a single number describing color difference. Larger values indicate larger perceptual differences. This calculator uses the simple CIE76 formula:
ΔE = √((ΔL*)² + (Δa*)² + (Δb*)²)
While newer formulas (CIE94, CIEDE2000) often improve perceptual matching, CIE76 is still useful for quick checks and educational work.
Practical interpretation tips
- ΔE < 1: Usually imperceptible
- 1–2: Barely perceptible under controlled viewing
- 2–10: Noticeable difference
- > 10: Strongly different colors
Always interpret these thresholds with context. Lighting conditions, material gloss, and observer sensitivity can shift what is considered acceptable.
LAB vs RGB in real projects
When RGB is enough
If your project lives entirely on screens and no strict color tolerance is required, RGB or HEX values may be sufficient.
When LAB is better
If color quality and consistency matter across devices and materials, LAB gives you a stronger foundation. It is especially useful in print production, scientific imaging, and manufacturing QC.
Final takeaway
A good LAB color space calculator does more than convert numbers—it gives you a reliable way to reason about color accuracy. Use the tool above to move between LAB and RGB, inspect XYZ values, and quickly estimate visual distance with Delta E.