An Analysis of Egg Size Variability

An Analysis of Egg Size Variability

Thomas Arend


Chicken eggs are a common staple in many diets and are used in a variety of recipes. Despite their widespread use, there is often variability in the size of chicken eggs within a single carton or batch. In this study, we aim to examine the variability in the size of eggs and identify factors that may contribute to these differences.

Chicken eggs are offered in the size classes S, M, L and XL. The main focus is on the two size classes M and L.

The size classes are defined as follows:

  • XL: 73 grams and more.
  • Large: 63 to under 73 grams.
  • Medium: 53 to under 63 grams.
  • Small: under 53 grams


  • Sample collection: A sample of eggs was collected from a local grocery store. The sample consisted of 36 eggs, classified as size L, and 6 eggs, size XL.
  • Data collection: The weight of the eggs was measured with a scale accurate to 0.01 grams. The measurements were taken in grams.
  • Data analysis: The collected data was analyzed to determine the average weight of the eggs and to calculate the standard deviation, which indicates the variability in the egg weights.


  • Average weight of eggs: The average weight of the eggs was 66,01 grams for eggs size L and 75.24 grams for eggs size XL.
  • Standard deviation: The standard deviation of the egg weights was 1.5636 grams for size L and 1.8243 gams for size XL.
  • With the exception of one egg size L, all eggs met the minimum weight for their size class. No egg was heavier than the maximum weight.
  • All but four of the eggs in the size class L were in the lower half of their size class.
  • The true mean of size L eggs is below the middle of the size class L, 68 grams, (p-value = 4,011e-9) .
  • Class XL eggs weigh not much more than the minimum weight requirement.


The number of size XL eggs was very low. Now eggs size M and S are included.


The results of this study indicate that there is low variability in the size of eggs within a single carton or batch. Class L eggs weigh less on average than the breadth of the size class suggests. This variability can impact the outcome of recipes and may lead to differences in cooking time and results.

Further research is needed to identify the factors that contribute to this variability, such as age of the eggs, the conditions under which the eggs are produced and stored, and the source of the eggs.


This study highlights the importance of carefully measuring the size of eggs when cooking and baking. It also underscores the need for further research to understand the factors that contribute to the variability in egg size and to identify ways to minimize this variability.


Eggs size L
Eggs size XL