Technology calculators

Delta E Calculator

Updated Sep 23, 2026 By Infinity Calculator
Rate Formulas
Reference Color (Standard)
Sample Color (Measurement)

Formula Settings

Graphic Arts uses kL = 1; Textiles uses kL = 2.
Lightness-to-chroma tolerance ratio for ΔECMC.
Results at or below this value are marked as Pass.
ΔE 2000 Weighting Factors
Delta E Results
Delta E Calculation Results
Formula ΔE Value Configuration Pass / Fail
Perceptual Interpretation

Delta E perceptual interpretation scale (row matching your ΔE 2000 result is highlighted)
ΔE Range Perceptual Meaning
Step-by-Step Solution
Formula Comparison vs. Tolerance

Introduction

The Delta E Calculator tells you how different two colors are. You type in the L*a*b* values for a reference color and a sample color. The tool then returns one number, called Delta E (ΔE), that shows the size of the color difference. A small number means the colors look almost the same. A big number means people will spot the difference right away.

This calculator runs four color difference formulas at once: ΔE*ab (CIE 1976), ΔE*94 (CIE 1994), ΔE CMC, and ΔE 2000 (CIEDE2000). Each one weighs lightness, chroma, and hue in its own way. ΔE 2000 matches human eyes the best, so most display and print labs use it today. You can pick a context for ΔE*94 (graphic arts or textiles), set the CMC ratio, and change the kL, kC, and kH weights for ΔE 2000.

Set your own pass/fail tolerance, and the tool marks each result as Pass or Fail. You also get color swatches, a chart, a plain-English guide to what your ΔE means, and full step-by-step math so you can check the work.

Use it for display calibration, monitor testing, printing, paint, plastics, and any job where colors must match a standard.

How to use our Delta E Calculator

Enter the L*a*b* values for your reference color and your sample color, then pick your formula settings. The tool shows the color difference (ΔE) using four formulas (ΔE*ab 1976, ΔE*94, ΔE CMC, and ΔE 2000), plus a pass/fail check, color swatches, a step-by-step solution, and a chart.

Reference L* (Lightness): Type the lightness of your standard color, from 0 (black) to 100 (white).

Reference a* (Green–Red): Type the green-to-red value of your standard color. Minus numbers are green, plus numbers are red.

Reference b* (Blue–Yellow): Type the blue-to-yellow value of your standard color. Minus numbers are blue, plus numbers are yellow.

Sample L* (Lightness): Type the lightness you measured on your test color or display.

Sample a* (Green–Red): Type the green-to-red value you measured on your sample.

Sample b* (Blue–Yellow): Type the blue-to-yellow value you measured on your sample.

ΔE*94 Application Context: Choose Graphic Arts (kL = 1) for print, screens, and coatings, or Textiles (kL = 2) for fabric work.

CMC Weighting Ratio (l:c): Pick 2:1 to test if a color is acceptable, or 1:1 to test if the eye can see the difference at all. 1.4:1 sits in between.

Pass/Fail Tolerance (ΔE): Enter the biggest color difference you allow. Any result at or under this number is marked Pass.

ΔE 2000 Weighting Factors (kL, kC, kH): Leave all three at 1 for normal use. Change them only if your standard or test method asks for other values.

Click Calculate ΔE to see your results, or Reset to go back to the sample values.

What Is Delta E?

Delta E (written ΔE) is a number that tells you how different two colors are. A small Delta E means the two colors look almost the same. A big Delta E means you can easily see they are different. Color experts use Delta E to check if a screen, print, or paint matches a target color.

How Delta E Works

Colors are first turned into three numbers called L*, a*, and b* (CIELAB):

  • L* is lightness. 0 is black and 100 is white.
  • a* goes from green (negative) to red (positive).
  • b* goes from blue (negative) to yellow (positive).

Think of these three numbers as a spot in a 3D space. Delta E is basically the distance between the two spots. The farther apart they sit, the bigger the color difference.

The Four Delta E Formulas

  • ΔE*ab (CIE 1976): The oldest and simplest. It is just straight-line distance. It is easy to compute, but it does not always match what your eyes see, especially for blues.
  • ΔE*94 (CIE 1994): An improved version. It weighs lightness, chroma (color strength), and hue differently. It has one setting for graphic arts and one for textiles.
  • ΔE CMC: Made by the Colour Measurement Committee for the textile trade. The l:c ratio sets how much lightness error you allow. Use 2:1 to judge if a match is good enough, and 1:1 to judge if a person can spot the difference at all.
  • ΔE 2000 (CIEDE2000): The most modern and the best match to human vision. Most display, print, and photo standards use it today. If you only look at one number, look at this one.

What the Numbers Mean

Delta EWhat you see
Less than 1.0The eye cannot tell them apart.
1.0 – 2.0Only a trained eye can spot it.
2.0 – 3.5Most people notice the difference.
3.5 – 5.0Clearly different colors.
Over 5.0The difference is obvious.

Where Delta E Is Used

Monitor and TV makers use Delta E to rate color accuracy. A good calibrated display keeps the average ΔE 2000 under 2, and pro work often asks for under 1. Printers use it to make sure ink matches the proof. Paint, plastic, car, and fabric makers use it so every batch looks the same as the last one.

Tolerance and Weighting Factors

A tolerance is the largest Delta E you will accept. Many shops set it at 2.0. Anything at or below that passes; anything above it fails. The kL, kC, and kH factors in ΔE 2000 let you loosen or tighten how much lightness, chroma, or hue error counts. Leave all three at 1 unless your standard tells you otherwise.

Formulas used

CIE 1976 color difference (ΔE*ab)
\Delta E^*_{ab} = \sqrt{(\Delta L^*)^2 + (\Delta a^*)^2 + (\Delta b^*)^2}
Chroma and hue difference terms
C^*_i = \sqrt{(a^*_i)^2 + (b^*_i)^2},\quad \Delta C^*_{ab} = C^*_2 - C^*_1,\quad \Delta H^*_{ab} = \sqrt{\left|(\Delta E^*_{ab})^2 - (\Delta L^*)^2 - (\Delta C^*_{ab})^2\right|}
CIE 1994 color difference (ΔE*94)
\Delta E^*_{94} = \sqrt{\left(\frac{\Delta L^*}{k_L S_L}\right)^2 + \left(\frac{\Delta C^*_{ab}}{k_C S_C}\right)^2 + \left(\frac{\Delta H^*_{ab}}{k_H S_H}\right)^2},\quad S_L = 1,\; S_C = 1 + K_1 C^*_1,\; S_H = 1 + K_2 C^*_1
CMC(l:c) color difference
\Delta E_{CMC} = \sqrt{\left(\frac{\Delta L^*}{l\,S_L}\right)^2 + \left(\frac{\Delta C^*_{ab}}{c\,S_C}\right)^2 + \left(\frac{\Delta H^*_{ab}}{S_H}\right)^2}
CMC weighting functions
S_L = \frac{0.040975\,L^*_1}{1 + 0.01765\,L^*_1}\;(L^*_1 \ge 16),\quad S_C = \frac{0.0638\,C^*_1}{1 + 0.0131\,C^*_1} + 0.638,\quad S_H = S_C\left(F\,T + 1 - F\right),\quad F = \sqrt{\frac{(C^*_1)^4}{(C^*_1)^4 + 1900}}
CIEDE2000 primed coordinates
G = \frac{1}{2}\left(1 - \sqrt{\frac{\bar{C}^7}{\bar{C}^7 + 25^7}}\right),\quad a' = (1+G)\,a^*,\quad C' = \sqrt{(a')^2 + (b^*)^2},\quad \Delta H' = 2\sqrt{C'_1 C'_2}\,\sin\!\left(\frac{\Delta h'}{2}\right)
CIEDE2000 weighting and rotation terms
S_L = 1 + \frac{0.015(\bar{L}'-50)^2}{\sqrt{20 + (\bar{L}'-50)^2}},\quad S_C = 1 + 0.045\bar{C}',\quad S_H = 1 + 0.015\bar{C}'T,\quad R_T = -\sin(2\Delta\theta)\cdot 2\sqrt{\frac{\bar{C}'^7}{\bar{C}'^7 + 25^7}}
CIEDE2000 color difference (ΔE00)
\Delta E_{00} = \sqrt{\left(\frac{\Delta L'}{k_L S_L}\right)^2 + \left(\frac{\Delta C'}{k_C S_C}\right)^2 + \left(\frac{\Delta H'}{k_H S_H}\right)^2 + R_T\,\frac{\Delta C'}{k_C S_C}\cdot\frac{\Delta H'}{k_H S_H}}

Frequently asked questions

What is a good Delta E for a computer monitor?

For most work, an average ΔE 2000 under 2 is good. That means color errors are hard for normal eyes to see.

  • Under 1: pro photo, video, and print work
  • 1 to 2: very good, fine for most design jobs
  • 2 to 3: okay for gaming and everyday use
  • Over 3: errors most people will notice

Factory-calibrated monitors often ship with a report showing average ΔE under 2.

What is the difference between average Delta E and maximum Delta E?

Average Delta E is the mean error across all the test colors you measured. Maximum Delta E is the worst single color in that set.

A screen can have a great average of 1.2 but still show one bad color at 6. That one color may be the skin tone or the blue you care about. Always check both numbers, not just the average.

How do you measure L*a*b* values for a color?

You need a measuring device:

  • Spectrophotometer: reads the full light spectrum. Best for paint, ink, plastic, and fabric.
  • Colorimeter: reads through red, green, and blue filters. Cheaper and fast, popular for screen calibration.

The device also needs settings: an illuminant (often D65 or D50) and an observer angle (2° or 10°). Both samples must use the same settings, or the Delta E means nothing.

Does the light source change Delta E?

Yes. L*a*b* values depend on the illuminant used, so the same two samples can give different Delta E numbers under D65 daylight and under store lighting.

Two colors can even match under one light and clash under another. That is called metamerism. This is why labs state the illuminant and observer with every Delta E result.

What is a just noticeable difference in color?

A just noticeable difference (JND) is the smallest color change a person can spot. In Delta E 2000 it is about 1.0 when two colors sit side by side with a sharp edge between them.

If the colors are apart, or split by a gap, most people need a Delta E of 2 or more before they notice.

Why does Delta E 2000 give a lower number than Delta E 1976?

Delta E 1976 treats all parts of color space the same. But CIELAB space is not even, so it over-reports errors in saturated colors, especially blues and reds.

Delta E 2000 adds weight terms for lightness, chroma, and hue, plus a rotation term for blue. These usually pull the number down to match what eyes really see. Both are correct math; ΔE 2000 just tracks human vision better.

Can Delta E be negative?

No. Delta E is a distance, so it is always zero or positive. Zero means the two colors have the exact same L*a*b* values.

The parts inside the formula can be negative. ΔL* of -3 means the sample is darker than the standard. But the final Delta E is always positive.

What do Delta L, Delta C, and Delta H tell you?

Delta E tells you how big the error is. These three tell you what kind of error it is, so you know what to fix.

  • ΔL*: plus means too light, minus means too dark
  • ΔC*: plus means too strong or bright, minus means too dull or gray
  • ΔH*: the hue shifted, so the color leans the wrong way (for example, red leaning orange)

A press operator can add ink for low chroma, but a hue error needs a different ink.

How do you convert RGB or a hex code to L*a*b*?

It takes three steps:

  1. Split the hex into R, G, B values from 0 to 255 and scale them to 0 to 1.
  2. Undo the gamma curve to get linear RGB, then use a matrix to get XYZ.
  3. Divide XYZ by the white point (like D65) and apply the cube-root CIELAB formula to get L*, a*, and b*.

You must know which RGB space the numbers come from. The same hex code gives different L*a*b* values in sRGB, Adobe RGB, and Display P3.

What Delta E is acceptable for printing?

Print standards use ΔE 2000. A common target for contract proofs is an average near 2.5 or lower, with no single patch over about 5. Solid primary inks are usually held tighter, around 3.5.

For repeat runs on press, many shops set a house rule of ΔE 2000 at 2 or under for brand colors, since customers notice logo colors fast.

What Delta E do paint and plastic makers use?

Car paint is the strictest. Body panels often need a Delta E near 1 or lower, because two panels sit right next to each other and the eye catches tiny shifts.

Wall paint and plastic parts are looser, often 1 to 2. Parts that are far apart in a product can pass at higher numbers. Many of these trades still use ΔE CMC 2:1 instead of ΔE 2000.

What causes a high Delta E on a display?

Common causes are:

  • No calibration or an old, stale profile
  • Wrong gamma or white point (for example, 9300K instead of 6500K)
  • Wide-gamut panel forced to show sRGB content without a proper mode
  • Backlight aging or warm-up time that is too short
  • Poor panel uniformity, so edges read worse than the center

Let the screen warm up for 30 minutes, set the right color mode, then calibrate with a meter.

Related Technology calculators

All Technology calculators
Technology

Aspect Ratio Calculator

Calculate aspect ratios instantly. Resize images & videos while maintaining proportions. Enter width and height to find your perfect aspect ratio.

Open Technology

PPI Calculator

Free PPI calculator to find pixels per inch for any display. Enter screen size and resolution to calculate PPI, pixel density, and display sharpness.

Open Technology

Projector Calculator

Calculate throw distance or image size from throw ratio and aspect ratio. Search 70+ projector models, check room depth fit, lens offset, screen gain.

Open Technology

Screen Size Calculator

Free screen size calculator to find display dimensions, aspect ratio, and area. Convert between inches, cm, and pixels for TVs, monitors, and phones.

Open