Haugh Units

You need to crack open an egg on a leveled plate of glass after weighing it in order to measure the haugh unit of an egg.

Then you need to measure the height of the albumen with the albumen height gauge with a distance of about 1cm to the yolk.

The formula for the calculation of Haugh-Units is:

{\displaystyle HU=100\cdot \log(h-1{,}7w^{0{,}37}+7{,}6)}


  • HU = Haugh-Unit
  • h = measured height of the albumen in mm
  • w = mass of the egg in gramm

The calculation is automated within our software.

You can read the data out of the table alternatively.

Screenshot of the Haugh-Unit-Software (PHUT)

Yolk colour

The egg yolk color is traditionally expressed in “Roche values” of 1 to 15.

The name “Roche” refers to the company Roche, which released the colour fan shown below a few years ago. Roche was acquired by DSM Nutrition Products GmbH a few years ago.

Our measurement devices work with a R-G-B-sensor which filtercurves work similiarly to the human eye (3-area method).

Using the red, green and blue ratio our software calculates the L*a*b data to determine the Roche-value. The software saves the L*a*b ratio and the Roche-value.

Shell strength

The shell thickness is determined with a special micrometer. A “normal” micrometer screw has two parallel measuring surfaces. These are unsuitable for the determination of the shell thickness due to the curvature of the eggshell.  Therefore we supply a special rounded contact surface. Matching the micrometer we offer a convenient holder for the micrometer.