Delta E CIE76 calculator
The simplest and oldest color difference metric, used for quick comparisons and in older specifications that still cite it.
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How to use it
- Enter reference l*, reference a*, reference b*, sample l*, sample a* and sample b*.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
ΔE*ab = √((L2 − L1)² + (a2 − a1)² + (b2 − b1)²).
Example
Inputs: Reference L* = 50, Reference a* = 2.5, Reference b* = 0, Sample L* = 73, Sample a* = 25. Result: ΔE*ab (CIE76): 36.868; ΔL* (sample minus reference): 23; Δa*: 22.5.
Limits and caveats
- CIE76 overstates differences between saturated colors and understates some blue differences, so CIEDE2000 is preferred for tight decisions.
Questions about this tool
What ΔE can a person notice?
About 2.3 is often quoted as a just noticeable CIE76 difference, but it varies a lot across color regions, so do not treat it as an acceptance limit.
Does the order of the colors matter?
Not for ΔE, since distance is symmetric. The signs of ΔL*, Δa* and Δb* flip if you swap reference and sample.
Where do I get Lab values?
From a spectrophotometer, or from the HEX to Lab converter on this site.