Eggs M or L. The shop counts pieces, the difference is in grams
Two boxes from the same brand sit next to each other on the egg shelf. Same free-range farming, same class A, same country of origin, ten eggs in each tray. One letter on the lid tells them apart.
- Moja Kurka free-range M, 10 pcs: 13.49 zł, that's 1.35 zł per egg
- Moja Kurka free-range L, 10 pcs: 13.99 zł, that's 1.40 zł per egg
- goBIO eggs, 9 pcs: 14.39 zł, that's 1.60 zł per egg (organic farming, a different shelf)
The shop works out those per-piece prices itself and prints them under the product name. It looks clear enough: M is five groszy cheaper per egg. Eggs are one of the few products where the shop shows no price per kilo, and a piece tells you nothing about how much food goes into your basket.
The letter on the lid is a weight range
Egg weight classes are set in Commission Regulation (EC) No 589/2008:
- S: under 53 g
- M: 53 to 63 g
- L: 63 to 73 g
- XL: 73 g and above
The classes don't overlap. The middle of M is 58 grams, the middle of L is 68, so roughly 17 percent more egg.
Per kilo it goes the other way
Ten M eggs weigh around 580 grams, ten L eggs around 680. From the pack price that gives:
- Class M: 13.49 zł for about 580 g, that's 23.26 zł per kilo
- Class L: 13.99 zł for about 680 g, that's 20.57 zł per kilo
The gap is 2.69 zł per kilo, 11.5 percent in favour of L. You pay 3.7 percent more and get about 17 percent more mass. Those are numbers with the shells on, but the shell doesn't disappear in either class, so the direction holds.
What it adds up to over a year
One pack a week works out like this. Fifty-two packs of M cost 701.48 zł and hold about 30.2 kilos of egg. Getting that same mass of egg in class L takes a little over 44 packs, so 620.50 zł. Eighty-one złoty a year on a single product, for changing one letter on the shopping list.
When M is the better buy
Recipes count eggs in pieces, and there the maths flips. Scrambled eggs from two M eggs cost 2.70 zł, the same from two L eggs 2.80 zł. If your breakfast is always two eggs and that's enough for you, M is simply cheaper.
Class L wins when mass matters rather than count: cakes, meatballs, an omelette for two, measured protein in a plan. Two L eggs weigh as much as two and a third M eggs.
To be fair, this compares the middle of each class. One particular M egg can weigh 62 grams and one particular L egg 64, and then five groszy buys you two grams. Across ten eggs those extremes even out.
When a price per piece is not enough
When a shop prices something per piece, it means it doesn't know the weight of what it sells. You have to supply the weight yourself, and with eggs it's printed on the lid as a letter.
Out of the 500 recipes in Snugmeal, eggs show up in 104. The plan counts them in grams rather than pieces, so you can see straight away how much food sits behind the price.
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Data: prices and product descriptions read live from product pages on zakupy.biedronka.pl on 17 August 2026. Weight classes per Commission Regulation (EC) No 589/2008 (the classes are also listed by WIJHARS Olsztyn on gov.pl). Prices per kilo calculated from the middle of each weight class, our own arithmetic.