Delta E Calculator (CIE76, CIE94, CIEDE2000)
Enter two colors in CIE L*a*b* coordinates. Choose a formula and click calculate.
What is Delta E?
Delta E (written as ΔE) is a numeric way to describe how different two colors are. Instead of saying “these look close,” you can measure the gap between them using color science. The lower the value, the closer the two colors appear.
In most workflows, you compare two points in Lab color space: one is your reference (target), and the other is the sample you measured. Delta E turns those two points into a single difference value.
How to interpret ΔE values
- < 1.0: Usually imperceptible to the human eye.
- 1.0 to 2.0: Very small difference; trained observers may notice.
- 2.0 to 3.5: Noticeable in side-by-side comparison.
- 3.5 to 5.0: Clear visual mismatch.
- > 5.0: Colors are obviously different.
Which formula should you use?
| Formula | Best use | Notes |
|---|---|---|
| CIE76 | Simple baseline calculations | Fast and easy, but less aligned with human perception. |
| CIE94 | Legacy print/textile workflows | Improves weighting for chroma and hue over CIE76. |
| CIEDE2000 | Modern quality control and color management | Most perceptually uniform in many practical scenarios. |
Step-by-step: calculating Delta E from Lab values
1) Measure or obtain Lab coordinates
Use a spectrophotometer or trusted conversion pipeline to get L*, a*, and b* for both colors. Accuracy here matters more than anything else.
2) Pick a tolerance target
Decide what “acceptable” means for your context. Packaging, automotive paint, and brand print standards can all have different thresholds.
3) Apply the formula consistently
Don’t compare CIE76 values to CIEDE2000 tolerances. Keep formula and tolerance paired in your SOP.
4) Make decisions from trend + threshold
A single reading can be noisy. In production, track batch averages and variance, not just one data point.
Common mistakes when calculating ΔE
- Mixing up RGB and Lab (Delta E formulas are generally applied in Lab space).
- Comparing results from different formulas as if they were equivalent.
- Ignoring illuminant/observer conditions when converting to Lab.
- Using uncalibrated devices for color capture.
- Applying one universal tolerance to every material and finish.
Practical tip for teams
Document your full color workflow: illuminant, observer, instrument, formula, and acceptance range. That one-page standard prevents most quality disputes and saves time across design, prepress, and manufacturing.
Bottom line
Calculating Delta E gives you an objective way to evaluate color differences. Use CIEDE2000 when possible, keep your measurement process consistent, and define clear tolerances for your specific application.