Interesting that egg sizing labels aren’t that universal. In the U.S. most big stores primarily stock Large (minimum weight 56.7g) and Extra Large (63.8g), while Jumbo (70.9g) is still probably more common than Medium (49.6g).
(My methodology for getting weights was that I used the government labeling requirements for minimum weight per dozen, converted ounces to grams, divided by 12).
Our ranges are S for anything below 53g, M to just below 63g, L to just below 73g, and XL for anything 73g and up. I had eggs in the 85+g range from that farm shop occasionally (that must have been a monster chicken!), and even one 10-pack with 7 double yolk eggs once.
Once they had an offer of size S eggs, and even small ones for that group. They were not much bigger than Quail eggs and from the first layings of young hens. I bought a box of them for fun and fried three of them for breakfast. My son took a look at the tiny little egglet I placed on his plate and he asked me what I had done to the rest of the egg…